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Date Category: Physics
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
- Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear.
- If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines).
- Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Source: https://Information-Technology.ru/sci-pop-articles/23-physics/231-pochemu-magnit-prityagivaet-zhelez
Difference between neodymium magnet and ordinary magnet
The main difference between neodymium magnet and ordinary magnet is that neodymium magnet contains neodymium, iron and boron as the key chemical elements, while ordinary magnet contains iron as the main chemical element.
A neodymium magnet is a type of magnet with strong magnetism made from rare earth elements such as neodymium. It is an alloy of several metals such as iron, boron, etc. Whereas, conventional magnets are ceramic magnets which contain ferrite as the main compound. It contains a high percentage of iron(III) oxide along with some other metals such as barium. These magnets are popular due to their low cost and fairly high magnetism strength.
- Overview and main differences
- What is a neodymium magnet
- What is a regular magnet
- What is the difference between a neodymium magnet and a regular magnet
- Conclusion
What is a neodymium magnet?
A neodymium magnet is a type of rare earth magnet that contains neodymium, iron and boron. This is a permanent magnet. It has an alloy of these metals in the form of a tetragonal crystal structure Nd2Fe14B. This magnet is the strongest commercial grade magnet currently available. Therefore, these magnets can replace many other types of magnets in modern products such as motors in cordless tools.
Neodymium is a ferromagnetic material; so we can magnetize it so that it becomes a magnet. However, the Curie temperature (the material at which a magnet loses magnetism) of this element is very low. Therefore, in its pure form it exhibits magnetism at very low temperatures. But if we make an alloy of neodymium with some transition metals such as iron, we can improve the magnetism of this material. This is a “neodymium magnet”.
Neodymium magnetic balls
There are several factors that determine the strength of this magnet. The main factor is the tetragonal crystal structure of this alloy.
In addition, the neodymium atom also has a significant magnetic dipole moment due to the presence of 4 unpaired electrons.
In addition to this, these magnets have exceptionally high residual coefficient (magnetic field strength), coercivity (material's resistance to demagnetization) and magnetic energy density. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively low.
What is a regular magnet?
Regular magnets are magnets that we use for common purposes. In most cases we use ceramic (or ferrite) magnets. These magnets contain ferrite as the main component. Ferrite is a ceramic material. It is mainly composed of iron(III) oxide. and there are also some other metals such as barium, manganese, nickel and zinc. These components are ferromagnetic and electrically non-conductive.
Ceramic magnets
In addition, these magnets have a relatively low residual magnetic induction (magnetic field strength) and coercive force (material resistance to demagnetization). But there are two types of ferrite magnets: hard ferrites and soft ferrites depending on the coercivity (high and low respectively). The magnetic energy density is also very low. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively high.
Source: https://raznisa.ru/raznica-mezhdu-neodimovym-magnitom-i-obychnym-magnitom/
How a magnet affects us: the whole truth about magnetic jewelry
Nowadays, treatment is mainly based on medications. Pharmacy shelves are filled with various tablets, capsules, syrups and drops.
In addition to their beneficial effect, they have many side effects on the body: they overload the liver and kidneys, and negatively affect the immune system. In addition, they are addictive, so when their therapeutic effect is needed most, there is no need to wait for it.
Of course, we are mainly talking about patients with chronic pathology, which requires constant monitoring and correction of the condition, and systematic use of medications.
In order to relieve the body of medications, but at the same time “keep the disease in check,” more and more doctors are trying to dilute the treatment with physiotherapy. There are many similar techniques, each with its own vectors of work. In this article we will take a closer look at magnetic therapy.
History of magnetic therapy
Magnetotherapy is a physiotherapeutic technique based on the effect of a magnetic field on the human body.
Since ancient times, people have been interested in magnetic fields. Their existence was first noticed about 2 thousand years ago. Over time, it found practical application in the form of a compass. According to historical documents, it was first noticed in China 1 thousand years before the new era that a long piece of magnetic iron attached to a plug floating in a liquid pointed north.
Since then, people began to find new uses for this important invention. Without it, it would have been impossible to create cars, ships, tape recorders, etc. In medicine, the magnet also played an undeniable role.
Doctors of ancient times (immediately after the discovery of the properties of a magnet) began to study its effect on the human body. Initially, data on its properties for humans were contradictory. Some considered the magnet a potent poison, while others considered it a panacea. The history of medicine knows many cases of the use of magnets as a remedy:
- Hippocrates used magnetic powder as a laxative.
- Cleopatra constantly wore a magnetic necklace, which was supposed to preserve her beauty and youth.
- Queen Elizabeth I suffered from arthritis. According to the documents, she was treated with magnets.
- Franz Antoine Mesmer cured many people using magnets. He successfully practiced in Vienna and Paris, where, as part of the team of the Royal Society of Medicine, he tried to use this technique to heal people with seizures and nervous diseases. They used magnets in the form of rings, bracelets, and amulets. After conducting many experiments, Mesmer came to the conclusion that our body is surrounded by a magnetic field, and direct influence on it can help cure many diseases.
- After the Civil War, there was a real shortage of qualified medical personnel in the United States. This led to the spread of folk remedies. Magnets were especially popular. They were used in the form of insoles, bandages, and rings. They have been successfully used as a pain reliever.
- At the beginning of the 19th century, more and more articles began to appear scientifically substantiating the use of magnetic therapy.
Nowadays, this type of physiotherapy has become especially widespread in the USA, China, and Japan. Many means, methods and types of magnetic therapy have been developed, which are successfully used in various branches of medicine.
Scientific rationale for magnetic therapy
How and why does it work? How can a small bracelet help you cure a huge list of diseases?
Thanks to physics, we know that everything in the world has its own magnetic fields. Man is no exception. Our magnetic field is formed due to the flow of blood through the vessels. It consists of metal ions, which, when circulating, form a static magnetic field. It is present where there are blood vessels in our body, that is, absolutely everywhere.
When we are exposed to a magnetic field, electric currents are generated in the body. Because of this, a number of changes occur:
- changes in the configuration of cell membranes and their structural units (lysosomes, mitochondria, etc.);
- changes in cell membrane permeability;
- changes in the course of chemical reactions in the body that occur with the participation of free radicals (almost all processes in which enzymes are involved);
- changes in the physicochemical properties of all body fluids;
- reorientation of large molecules (including proteins, fats, carbohydrates).
By influencing these basic processes in the body, you can regulate its condition. Currently, many studies have been conducted that confirm the effectiveness of magnetic therapy. They make it possible to become an alternative to heavy medication load.
Types of magnetic therapy
Thanks to technological progress, several types of magnets are available to us that can be used for therapeutic purposes. Magnetic therapy is differentiated based on the type of magnetic fields: variable and constant. There is also a distinction between general magnetic therapy (when the effect occurs on the entire body as a whole) and local (the effect is carried out locally: on a joint, a separate organ or area).
If we talk about technical equipment, there are now three main types of devices available:
- Stationary. It consists of a table, a magnet and a computer, which contains several basic treatment protocols. The patient lies down on the table, and the physiotherapist selects the necessary protocol. The device can also be equipped with additional components (a magnet for local, directional influence, a belt, a solenoid that allows you to create a circular magnetic field). Treatment usually takes place in courses. One session lasts from 15 to 40 minutes. No special preparation is required. The only recommendation is to drink a glass of water before the procedure to slightly enhance the effect of the device.
- Portable. It is a device that the patient can easily carry with him. The effect is carried out by applying the device to the affected area of the body or wearing it in this area. The most popular device is considered to be “Magofon-01”, which creates special vibroacoustic vibrations and a low-frequency magnetic field. This type of device has pronounced analgesic, anti-edematous and anti-inflammatory effects.
- Magnetic jewelry. Patients wishing to purchase magnetic jewelry have a wide range of choices: rings, bracelets, necklaces, watches, earrings, brooches, etc. They are often elegantly and tastefully made. Naturally, it is difficult to suspect a medicinal product in these accessories. They are usually made of copper, metal, or jewelry steel. Active magnets are placed on their inner surface. It is the latter that have a special field; accordingly, they are made with extreme care in order to help and not harm a person.
The impact of magnetic jewelry on the human body
Magnets change our state at the molecular level. This affects the organs and their performance, which allows doctors to recommend them as an additional treatment for a number of pathologies.
The main beneficial therapeutic effects of magnetic jewelry include:
- Improving microcirculation. Blood circulation under the influence of magnetic fields improves throughout the body, including blood circulation in the brain. This effect is realized due to an increase in the lumen of the smallest vessels in our body - capillaries. At the same time, the speed of blood flow in vessels of medium and large caliber is optimized.
- Reduced blood viscosity. This effect helps prevent the formation of blood clots.
- Improving the permeability of the vascular wall. It also optimizes blood flow while slowly clearing cholesterol deposits from the blood vessels.
- Normalization of lymphatic drainage. Magnetic fields have a beneficial effect on lymphatic vessels, expanding their lumen. This promotes better lymph outflow, reducing tissue swelling and accelerating the process of removing by-products of metabolic processes.
- Stimulation of tissue nutrition. This implies that tissues begin to receive more nutrients when using magnetic jewelry. Metabolism at the cellular level is enhanced, which improves recovery and regeneration processes in the body.
- Anti-inflammatory effect. Reducing swelling, improving blood circulation in organs and optimizing the synthesis of anti-inflammatory substances (prostaglandins) contributes to a faster resolution of inflammatory processes in the body.
- Regulation of the nervous system. This technique allows you to activate the processes of excitation or inhibition of the nervous system, depending on the type of magnetic therapy and the point of application.
- Decreased sensitivity of pain receptors. The impact on this type of receptor allows magnetic jewelry to realize an analgesic effect. In addition, there are studies that clearly demonstrate that magnetic fields can lead to the regeneration of nerve fibers and improve the conduction of impulses through them.
For what diseases are magnetic jewelry recommended?
Considering these effects of magnetic jewelry, it is advisable to use them for diseases such as:
Pathology of the cardiovascular system |
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Pathology of the nervous system |
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Diseases of the bronchopulmonary system and ENT organs |
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Diseases of the musculoskeletal system |
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Diseases of the gastrointestinal tract |
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Pathology of the urinary and reproductive system |
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Oral diseases |
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Pathologies of the visual analyzer |
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Skin diseases |
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Endocrine system |
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Source: https://fitexpert.biz/magnity/
Why does a magnet attract - all about magnetic fields
Why does a magnet attract?
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles.
Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other. The north pole of one magnet repels the north pole of the other.
Magnetic and electric current
The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
Magnetic field lines
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road.
For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
Related materials:
Gravitational interaction
Electron movement and magnetic field
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the electron around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
Why materials are magnetic and not magnetic
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction. That is, each domain is a small magnet.
Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if we manage to orient the domains in one direction so that the forces of the magnetic fields add up, then watch out! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Interesting fact: the mineral iron ore is a natural magnet. But still, most magnets are made artificially.
What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field. As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet.
Related materials:
How are magnets made?
You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large horseshoe magnet. Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Source: https://kipmu.ru/pochemu-magnit-prityagivaet-ili-vse-o-magnitnyx-polyax/
Neodymium magnet: what does it mean and what is it made of, how to use
Neodymium magnet is the most powerful and permanent magnet, which contains rare earth neodymium, boron and iron. What is the complete definition of a magnet and its main advantages, what is its strength and what is its principle of operation? More on this later.
What it is
A neodymium magnet is a magnetic element that is composed of neodymium rare earth boron and iron material. It has a crystal structure, tetragonal shape and formula Nd2Fe14B.
Neodymium magnet is the most common type
It was first created by General Motors in 1982. It is the strongest permanent magnetic element, the power of which is several times greater than usual. Equipped with a large magnetic induction of 12,400 gauss.
Note! This is a brittle alloy with the formula NdFeB, as well as a hard nickel-plated protective layer and the corresponding class. It is very popular and comes in various forms.
Full material definition
Advantages
The most common neodymium magnet is one that has an iron oxide alloy, which has good heat resistance, high magnetic permeability and low cost. Equipped with color coding, high coercivity, powerful magnetic field to hold objects suspended, compact size, light weight, affordable and wide range of applications. Has a long service life.
If an ordinary magnet works for 10 years and can be demagnetized, then a neodymium magnet does not lose its properties after 100 years. Another advantage is the shape. This product has a horseshoe shape. It gives the device a long service life. As for the cost, these are expensive products, but the cost is justified by excellent performance and impeccable reliability.
Durability of work as one of the advantages
Force
It is worth pointing out that the strength contained in neodymium magnets is another advantage. She is tall and it is impossible to find a competitor to her. This is a record type of indicator, the increase of which is impossible. Power is generated during manufacturing. Magnetization occurs after the alloy is formed. Thanks to existing technologies, the alloy is magnetized in such a way that the magnet has incredibly high power and this figure reaches a record.
Note! Power is a relative philistine concept. The force is stable, but it is measured using instruments. In this case, the readings depend on the thickness of the surface and cleanliness. The separation angle can have some influence.
Strength as one of the advantages
Life time
The service life of the equipment, if used properly, is 30 years. Due to careless handling, the device may be damaged. The point is the lack of flexibility, as well as brittleness and cracking under heavy load. Falls, impacts, or reduced traction will reduce the life of the equipment. For this reason, it is necessary to avoid falls using parts that come into contact during movements.
Another extremely important point is the irreversible loss of magnetic properties due to heating. Therefore, grinding with cutting or drilling reduces the chain force and may ignite the alloy. If storage and operation are organized correctly, then magnetization is maintained for 10 years.
Long service life
Design
When answering the question of what a neodymium magnet is made of, we can point out that it is a rare earth element that contains an atom with lanthanide or actinide. The classic composition may still contain an additive.
It is used to increase strength with endurance and resistance to high temperatures. Boron is used in small quantities, iron is a binding element. Thanks to this composition, greater adhesion is obtained.
When connecting several ferrite rings, you can separate them with your hands. As for neodymium magnets, this cannot be done.
Composition of magnetic material
How are neodymium magnets magnetized?
The magnetization of neodymium magnets occurs through the interaction of bromine ions, iron and neodymium in a powerful magnetic field. Thanks to such actions, an element is obtained that has a high coercive force and high adhesion power. It also has an extremely long service life in everyday life.
Magnetization of neodymium materials
Principle of operation
A neodymium magnet works very simply. If two magnetic elements are connected and the poles coincide in direction, the magnetic force of the two fields will be enhanced. The result is an overall strong magnetic field. With the reverse arrangement of the magnetized elements, the magnetic field will be suppressed.
Principle of operation
How to use
Neodymium magnetic element is the strongest, exceeding analogues that are based on rare earth metal. In addition, neodymium is capable of maintaining a magnetized structure for a significantly long time. Such equipment can be used in various fields. For example, it is used in the manufacture of over-ear headphones with wind generators, motor wheels and scooters.
Note! Magnets are actively used in industrial, household, and medical fields. They are also used to carry out search work with a metal detector. They can often be found in plumbing fixtures or souvenirs.
Specific examples include the use of magnets in the development of medical devices, magnetic treatment of water, the creation of oil and technological filters, and the formation of actuators with highly sensitive sensors. In addition, they are needed to produce clothes with covers and shoes, and to create advertising, information and navigation materials.
Scope of application of the material
Overall, neodymium is the most powerful permanent magnetic material that has high resistance to demagnetization, attractive power, and a metallic appearance. It has a long service life and consists of boron, iron and a metal of the lanthanide group.
Source: https://rusenergetics.ru/polezno-znat/neodimovykh-magnitakh
Permanent magnets, their description and principle of operation:
Along with pieces of amber electrified by friction, permanent magnets were for ancient people the first material evidence of electromagnetic phenomena (lightning at the dawn of history was definitely attributed to the sphere of manifestation of immaterial forces).
Explaining the nature of ferromagnetism has always occupied the inquisitive minds of scientists, however, even now the physical nature of the permanent magnetization of some substances, both natural and artificially created, has not yet been fully revealed, leaving a considerable field of activity for modern and future researchers.
Traditional materials for permanent magnets
They have been actively used in industry since 1940 with the advent of alnico alloy (AlNiCo). Previously, permanent magnets made of various types of steel were used only in compasses and magnetos. Alnico made it possible to replace electromagnets with them and use them in devices such as motors, generators and loudspeakers.
This penetration into our daily lives received a new impetus with the creation of ferrite magnets, and since then permanent magnets have become commonplace.
The revolution in magnetic materials began around 1970, with the creation of the samarium-cobalt family of hard magnetic materials with previously unheard-of magnetic energy densities.
Then a new generation of rare earth magnets was discovered, based on neodymium, iron and boron, with a much higher magnetic energy density than samarium cobalt (SmCo) and at an expectedly low cost.
These two families of rare earth magnets have such high energy densities that they can not only replace electromagnets, but be used in areas that are inaccessible to them. Examples include the tiny permanent magnet stepper motor in wristwatches and the sound transducers in Walkman-type headphones.
The gradual improvement in the magnetic properties of materials is shown in the diagram below.
Neodymium permanent magnets
They represent the latest and most significant development in this field over the past decades. Their discovery was first announced almost simultaneously at the end of 1983 by metal specialists from Sumitomo and General Motors. They are based on the intermetallic compound NdFeB: an alloy of neodymium, iron and boron. Of these, neodymium is a rare earth element extracted from the mineral monazite.
The enormous interest that these permanent magnets have generated arises because for the first time a new magnetic material has been produced that is not only stronger than the previous generation, but is more economical.
It consists mainly of iron, which is much cheaper than cobalt, and neodymium, which is one of the most common rare earth materials and has more reserves on Earth than lead.
The major rare earth minerals monazite and bastanesite contain five to ten times more neodymium than samarium.
Physical mechanism of permanent magnetization
To explain the functioning of a permanent magnet, we must look inside it down to the atomic scale. Each atom has a set of spins of its electrons, which together form its magnetic moment.
For our purposes, we can consider each atom as a small bar magnet. When a permanent magnet is demagnetized (either by heating it to a high temperature or by an external magnetic field), each atomic moment is oriented randomly (see Fig.
below) and no regularity is observed.
When it is magnetized in a strong magnetic field, all atomic moments are oriented in the direction of the field and, as it were, interlocked with each other (see figure below). This coupling allows the permanent magnet field to be maintained when the external field is removed, and also resists demagnetization when its direction is changed. A measure of the cohesive force of atomic moments is the magnitude of the coercive force of the magnet. More on this later.
In a more in-depth presentation of the magnetization mechanism, one does not operate with the concepts of atomic moments, but uses ideas about miniature (of the order of 0.001 cm) regions inside the magnet, which initially have permanent magnetization, but are randomly oriented in the absence of an external field, so that a strict reader, if desired, can attribute the above physical The mechanism is not related to the magnet as a whole. but to its separate domain.
Induction and magnetization
The atomic moments are summed up and form the magnetic moment of the entire permanent magnet, and its magnetization M shows the magnitude of this moment per unit volume. Magnetic induction B shows that a permanent magnet is the result of an external magnetic force (field strength) H applied during primary magnetization, as well as an internal magnetization M due to the orientation of atomic (or domain) moments. Its value in the general case is given by the formula:
B = µ0 (H + M),
where µ0 is a constant.
In a permanent ring and homogeneous magnet, the field strength H inside it (in the absence of an external field) is equal to zero, since, according to the law of total current, the integral of it along any circle inside such a ring core is equal to:
H∙2πR = iw=0, whence H=0.
Therefore, the magnetization in a ring magnet is:
M = B/µ0.
In an open magnet, for example, in the same ring magnet, but with an air gap of width lzaz in a core of length lser, in the absence of an external field and the same induction B inside the core and in the gap, according to the law of total current, we obtain:
Hser l ser + (1/ µ0)Blzaz = iw=0.
Since B = µ0(Hser + Mser), then, substituting its expression into the previous one, we get:
Hser(l ser + lzaz) + Mser lzaz=0,
or
Hser = ─ Mser lzaz(l ser + lzaz).
In the air gap:
Hzaz = B/µ0,
wherein B is determined by the given Mser and the found Hser.
Magnetization curve
Starting from the unmagnetized state, when H increases from zero, due to the orientation of all atomic moments in the direction of the external field, M and B quickly increase, changing along section “a” of the main magnetization curve (see figure below).
When all atomic moments are equalized, M comes to its saturation value, and a further increase in B occurs solely due to the applied field (section b of the main curve in the figure below).
When the external field decreases to zero, the induction B decreases not along the original path, but along section “c” due to the coupling of atomic moments, tending to maintain them in the same direction. The magnetization curve begins to describe the so-called hysteresis loop.
When H (external field) approaches zero, the induction approaches a residual value determined only by atomic moments:
Br = μ0 (0 + Mg).
After the direction of H changes, H and M act in opposite directions and B decreases (part of the curve “d” in the figure). The value of the field at which B decreases to zero is called the coercive force of the BHC magnet.
When the magnitude of the applied field is large enough to break the cohesion of the atomic moments, they are oriented in the new direction of the field, and the direction of M is reversed. The field value at which this occurs is called the internal coercive force of the permanent magnet MHC.
So, there are two different but related coercive forces associated with a permanent magnet.
The figure below shows the basic demagnetization curves of various materials for permanent magnets. It shows that NdFeB magnets have the highest residual induction Br and coercive force (both total and internal, i.e., determined without taking into account the strength H, only by the magnetization M).
Surface (ampere) currents
The magnetic fields of permanent magnets can be considered as the fields of some associated currents flowing along their surfaces. These currents are called Ampere currents. In the usual sense of the word, there are no currents inside permanent magnets.
However, comparing the magnetic fields of permanent magnets and the fields of currents in coils, the French physicist Ampere suggested that the magnetization of a substance can be explained by the flow of microscopic currents, forming microscopic closed circuits.
And indeed, the analogy between the field of a solenoid and a long cylindrical magnet is almost complete: there is a north and south pole of a permanent magnet and the same poles of the solenoid, and the patterns of force lines of their fields are also very similar (see figure below).
Are there currents inside a magnet?
Let's imagine that the entire volume of a bar permanent magnet (with an arbitrary cross-sectional shape) is filled with microscopic Ampere currents. A cross section of a magnet with such currents is shown in the figure below. Each of them has a magnetic moment. With the same orientation in the direction of the external field, they form a resulting magnetic moment that is different from zero.
It determines the existence of a magnetic field in the apparent absence of ordered movement of charges, in the absence of current through any cross section of the magnet. It is also easy to understand that inside it, the currents of adjacent (contacting) circuits are compensated. Only the currents on the surface of the body, which form the surface current of a permanent magnet, are uncompensated.
Its density turns out to be equal to the magnetization M.
How to get rid of moving contacts
The problem of creating a contactless synchronous machine is known. Its traditional design with electromagnetic excitation from the poles of a rotor with coils involves supplying current to them through movable contacts - slip rings with brushes.
The disadvantages of such a technical solution are well known: they are difficulties in maintenance, low reliability, and large losses in moving contacts, especially when it comes to powerful turbo and hydrogen generators, the excitation circuits of which consume considerable electrical power.
If you make such a generator using permanent magnets, then the contact problem immediately goes away. However, there is a problem of reliable fastening of magnets on a rotating rotor. This is where the experience gained in tractor manufacturing can come in handy. They have long been using an inductor generator with permanent magnets located in rotor slots filled with a low-melting alloy.
Permanent magnet motor
In recent decades, DC motors have become widespread. Such a unit consists of the electric motor itself and an electronic commutator for its armature winding, which performs the functions of a collector.
The electric motor is a synchronous motor with permanent magnets located on the rotor, as in Fig. above, with a stationary armature winding on the stator.
Electronic switch circuitry is an inverter of direct voltage (or current) of the supply network.
The main advantage of such a motor is its non-contact nature. Its specific element is a photo-, induction or Hall rotor position sensor that controls the operation of the inverter.
Source: https://syl.ru/article/203617/new_postoyannyie-magnityi-ih-opisanie-i-printsip-deystviya
What metals are not magnetic and why?
Any child knows that metals are attracted to magnets. After all, they have more than once hung magnets on the metal door of the refrigerator or letters with magnets on a special board. However, if you put a spoon against a magnet, there will be no attraction. But the spoon is also metal, so why does this happen? So, let's find out which metals are not magnetic.
Scientific point of view
To determine which metals are not magnetic, you need to find out how all metals in general can relate to magnets and a magnetic field. With respect to the applied magnetic field, all substances are divided into diamagnetic, paramagnetic and ferromagnetic.
Each atom consists of a positively charged nucleus and negatively charged electrons. They move continuously, which creates a magnetic field. The magnetic fields of electrons in one atom can enhance or cancel each other, depending on the direction of their movement. Moreover, the following can be compensated:
- Magnetic moments caused by the movement of electrons relative to the nucleus are orbital.
- Magnetic moments caused by the rotation of electrons around their axis are spin moments.
If all magnetic moments are equal to zero, the substance is classified as diamagnetic. If only spin moments are compensated - to paramagnets. If the fields are not compensated, use ferromagnets.
Paramagnets and ferromagnets
Let's consider the option when each atom of a substance has its own magnetic field. These fields are multidirectional and compensate each other. If you place a magnet next to such a substance, the fields will be oriented in one direction. The substance will have a magnetic field, a positive and a negative pole.
Then the substance will be attracted to the magnet and can itself become magnetized, that is, it will attract other metal objects. For example, you can magnetize steel clips at home. Each one will have a negative and a positive pole, and you can even hang a whole chain of paper clips on a magnet.
Such substances are called paramagnetic.
Ferromagnets are a small group of substances that are attracted to magnets and are easily magnetized even in a weak field.
Diamagnets
In diamagnetic materials, the magnetic fields inside each atom are compensated. In this case, when a substance is introduced into a magnetic field, the movement of electrons under the influence of the field will be added to the natural movement of electrons. This movement of electrons will cause an additional current, the magnetic field of which will be directed against the external field. Therefore, the diamagnetic material will be weakly repelled from the nearby magnet.
So, if we approach the question from a scientific point of view, which metals are not magnetic, the answer will be – diamagnetic.
Distribution of paramagnets and diamagnets in the periodic table of Mendeleev elements
The magnetic properties of simple substances change periodically with increasing atomic number of the element.
Substances that are not attracted to magnets (diamagnets) are located mainly in short periods - 1, 2, 3. Which metals are not magnetic? These are lithium and beryllium, and sodium, magnesium and aluminum are already classified as paramagnetic.
Substances that are attracted to magnets (paramagnets) are located mainly in the long periods of the Mendeleev periodic system - 4, 5, 6, 7.
However, the last 8 elements in each long period are also diamagnetic.
In addition, three elements are distinguished - carbon, oxygen and tin, the magnetic properties of which are different for different allotropic modifications.
In addition, there are 25 more chemical elements whose magnetic properties could not be established due to their radioactivity and rapid decay or the complexity of synthesis.
The magnetic properties of lanthanides and actinides (all of which are metals) change irregularly. Among them there are para- and diamagnetic materials.
There are special magnetically ordered substances - chromium, manganese, iron, cobalt, nickel, the properties of which change irregularly.
What metals are not magnetic: list
There are only 9 ferromagnets, that is, metals that are highly magnetic, in nature. These are iron, cobalt, nickel, their alloys and compounds, as well as six lanthanide metals: gadolinium, terbium, dysprosium, holmium, erbium and thulium.
Metals that are attracted only to very strong magnets (paramagnetic): aluminum, copper, platinum, uranium.
Since in everyday life there are no such large magnets that would attract a paramagnetic material, and also no lanthanide metals are found, we can safely say that all metals except iron, cobalt, nickel and their alloys will not be attracted to magnets.
So, what metals are not magnetic to a magnet:
- paramagnetic materials: aluminum, platinum, chromium, magnesium, tungsten;
- diamagnetic materials: copper, gold, silver, zinc, mercury, cadmium, zirconium.
In general, we can say that ferrous metals are attracted to a magnet, non-ferrous metals are not.
If we talk about alloys, then iron alloys are magnetic. These primarily include steel and cast iron. Precious coins can also be attracted to a magnet, since they are not made of pure non-ferrous metal, but of an alloy that may contain a small amount of ferromagnetic material. But jewelry made of pure non-ferrous metal will not be attracted to a magnet.
What metals do not rust and are not magnetic? These are ordinary food grade stainless steel, gold and silver items.
Source: https://FB.ru/article/435941/kakie-metallyi-ne-magnityatsya-i-pochemu
Why do magnets demagnetize - Metals and their processing
Employees of the site p-magnit.ru are sometimes asked about how to make a neodymium magnet with your own hands. Let's try to figure out how possible this is, and what the process of producing such products is all about.
So, the devices we sell consist of an alloy that is 70% iron and almost 30% boron. Only a fraction of a percent in its composition is made up of the rare earth metal neodymium, natural deposits of which are extremely rare in nature. Most of them are in China; they are found in only a few other countries, including Russia.
Before making neodymium magnets, manufacturers create molds for them from sand. Then the tray with the molds is doused with gas and subjected to heat treatment, due to which the sand hardens and retains the future outlines of the metal workpiece on its surface. Hot metal will later be placed in these forms, from which, in fact, the necessary products will be obtained.
Now let's directly look at how a neodymium magnet is made. Unlike ferromagnetic products, the metal here is not melted, but sintered from a powder mixture placed in an inert or vacuum environment.
Then the resulting magnetoplast is pressed while simultaneously exposing it to an electromagnetic field of a certain intensity. As you can see, even at the initial stage of production, it is noticeable that the question of how to make neodymium magnets at home sounds inappropriate.
The operations and equipment used are too complex. Creating such conditions at home is hardly possible.
After the workpieces are removed from the molds, they are subjected to mechanical processing - they are carefully polished, then they are fired to improve the coercive force of the products.
Finally, we come to the last steps, which will help to finally answer the question of how neodymium magnets are made. The sintered NdFeB alloy is again machine-finished using a special tool. During operation, a cooling lubricant is used to prevent overheating or ignition of the powder.
A protective coating is applied to the magnets. This is due, firstly, to the fact that sintered metals are quite fragile and need to be strengthened, and, secondly, the metal will be protected from corrosion processes and other environmental influences.
So manufacturers worry in advance about how to make a neodymium magnet stronger and more durable. The coating can be copper, nickel, zinc. In the last phase of the production process, magnetization is applied through a strong magnetic field.
Then they are sent to the warehouse, and from there to customers.
So, after we examined the production process in more or less detail, it became clear that we probably shouldn’t seriously ask the question “how to make a neodymium magnet at home.” After all, this requires not only certain knowledge, but many complex units.
How to completely demagnetize a neodymium magnet
Neodymium magnets are very popular in modern industry and in solving a number of everyday problems. If the buyer (for example) chose strong magnets for delivery in St. Petersburg, but violated the storage or transportation conditions, as a result of which they stuck together, it may be necessary to carry out a demagnetization procedure. The same action may be necessary in other cases when it is necessary for the product to lose its qualities.
The process can be carried out in various ways, including using factory equipment, and it is necessary to decide how to demagnetize a neodymium magnet taking into account your capabilities.
Methods for demagnetizing a magnet
Loss of the ability to attract metal objects can occur both naturally and during a number of actions. Subject to the rules of operation and storage, the qualities of neodymium elements are maintained for 100 years or more, and ferrite analogues continue to attract metal for 8-10 years. Degaussing neodymiums naturally is not practical if the procedure is to be performed on a new item.
THIS IS INTERESTING: Magnets for welding
Product heating
This method is used both in industrial and domestic conditions: if the magnet is made of a standard alloy of neodymium with boron and iron, it will lose its properties when placed in water boiling at 80 degrees Celsius or in case of contact with a surface heated to the specified temperature.
If we are talking about a product with increased resistance to thermal shocks, it is unlikely that it will be possible to perform the procedure at home: the demagnetization temperature of neodymium magnets with such properties is 200 degrees Celsius.
To carry out the procedure in such cases, special industrial equipment is used.
Mechanical Actions
Neodymium can lose its qualities as a result of a strong directed impact, for example, an impact: this material has a powder structure that is destroyed when dropped from a height or when exposed to impact equipment. In addition, demagnetization can occur accidentally during the process of drilling or cutting a magnet: this is due to excessive mechanical pressure or an increase in the temperature of the product without forced cooling.
Treatment with external magnetic influence
Most often, if it is possible to use industrial equipment of increased power, another magnet is used, which allows the formation of a field with an induction force of about 4 Tesla. A neodymium magnet is demagnetized in a matter of seconds, so this method, despite its technological complexity, is characterized by the fastest possible result.
How to magnetize demagnetized neodymium
If the demagnetization of an element occurs accidentally, and it is necessary to return the product to its properties, it is impossible to do this at home. Restoring a neodymium magnet requires the use of a product that can create a very powerful field, and this requires the use of professional equipment used to create such items.
Usually, if you need to return the magnetization properties for a specific element, you contact a factory that specializes in the production of such products.
Is there anything I can do to make the magnet stronger?
If neodymium used for household purposes has become demagnetized, often a more appropriate solution would be to purchase a new element. The cost of magnetization work varies depending on the required properties and pricing policy of a particular production.
Application of neodymium magnet
These products are available in various shapes and sizes and are used for the following tasks:
- Creating a clamping effect, fixing metal elements to each other. Using neodymium magnets, you can attach an antenna, license plate, plate, other metal part, device or entire mechanism.
- Filtration of oil systems in cars and other equipment: neodymium magnets allow you to easily and quickly remove metal shavings.
- Creation of magnetic locks and fasteners used in industrial sectors and household purposes.
- Search work related to the search for metal objects (search for treasures, historical values, weapons, mine clearance work, etc.).
- Restoring other magnetic elements: using a neodymium element, you can create a magnetic field that will return the product to its ability to attract metal.
- Deleting information recorded on floppy disks, disks, flash drives and other electronic media for security purposes.
- Creation of devices for universal use (hangers, stirring devices, compasses, etc.).
- Construction of current generators that can be used as experimental models or devices suitable for domestic use.
- Making jewelry: Neodymium can come in different shapes and sizes, and beads made from this material are often given a chrome finish and can be painted in different colors.
- Treatment of water using magnetic influence, as a result of which the formation of scale is reduced, and the liquid itself acquires an improved taste and smell.
- Fuel conditioning, which allows you to reduce fuel consumption for cars and motorcycles.
- Sorting small metal items that need to be removed from a variety of non-metal items.
THIS IS INTERESTING: Is copper magnetic or not?
Conclusion
Neodymium magnets are products that are widely used in commercial, industrial and household applications, they are characterized by high load capacity, excellent attractive properties and durability.
Before demagnetizing neodymium magnets, it is important to make sure that you have the necessary equipment: this requires either an industrial installation or a device for heating to at least 80 degrees.
Magnetizing products that have lost their quality is rarely advisable, but if necessary, you can order the procedure by contacting the manufacturer.
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Source: https://magnetline.ru/metally-i-splavy/pochemu-magnity-razmagnichivayutsya.html
Why putting a magnet on a meter is a bad idea
To reduce water and electricity bills, some people put powerful magnets on their meters. Under the influence of a magnetic field, even during the consumption of water and light, the device does not rotate.
But a magnet is not an innocent way to save money. If a person uses water and electricity, but does not pay for them, he steals, that is, he commits an administrative offense. In the laws, this is called theft and is punishable by a fine, temporary arrest or community service.
Inspectors will probably know about the magnet
It seems that if you install a magnet only occasionally and pay a little on the bills, then no one will know about the violation. But inspectors have several ways to detect theft:
- See the magnet. Usually they try not to let the inspectors in or quickly remove the magnet before opening the doors. But it may happen that the person who placed it will not be at home, the door will be opened by a child or a grandmother who has come to stay, or the residents will simply forget about the magnet. Then the inspector will take a photo of the violation and draw up a report, and then you will be issued a fine.
- Check the indicator. Modern water and light meters have special indicators, or magnetic field sensors. It is enough to bring a powerful magnet to the meter once - and the indicator will change color forever. And some of the most modern devices can even send a message to the dispatcher, so they will instantly know about the magnet.
- Measure the magnetic field. If a magnet has recently been placed on the meter, the magnetic field around it will be abnormally large. It can be measured using a special device - a Teslameter. And if the indicator can sometimes somehow be fooled, then the Teslameter cannot be fooled: it will clearly indicate that there was a magnet on the meter.
The Teslameter is expensive and is still rarely used, but gradually this method is becoming more and more popular. You can especially often find inspectors with teslameters in Moscow and St. Petersburg.
To record a violation and draw up a report, inspectors must come to the meter in person. To do this, management companies (MCs) arrange scheduled inspections every 1–2 years. Theoretically, you can adapt to them and use the magnet only immediately after the inspectors’ visit in order to save at least a little.
But if according to the general building meter the resource consumption is the same, but according to the sum of the apartment meters it is significantly less, this indicates theft on the part of the residents. In this case, the management company can arrange an unscheduled inspection and detect the magnet.
You will be punished for installing a magnet
Most often, on the basis of Government Resolution No. 354, they are required to pay the cost of resources tenfold. The cost is calculated according to average standards and multiplied by the time that has passed since the last inspection, but by a maximum of 3 months.
That is, if you install a magnet and it is discovered in six months, you will be forced to pay 10 times more than you would pay according to the standards for three months. Standards, by the way, are often too high.
Usually people spend less than the average per month, so the overpayment will be large.
This fine is not related to theft - it only relates to violation of the meter. If the Criminal Code decides to sue, the violator faces the following penalties:
- A fine of 10–15 thousand rubles for the unauthorized use of electrical, thermal energy, oil or gas, according to the Administrative Code.
- A fine of five times the value of the stolen property for petty theft up to 1 thousand rubles, according to the Administrative Code.
- A fine for petty theft is from 1 to 2.5 thousand rubles in the amount of five times the value of the stolen property, or arrest for 10–15 days, or up to 120 hours of community service.
Theoretically, when more than 2.5 thousand rubles are stolen, the crime is no longer considered administrative, but criminal. He faces a fine of up to 300 thousand rubles or imprisonment for 1–2 years. But in fact, such punishments are not imposed in the Russian Federation for magnets on meters.
You can save money without a magnet
To save money, you don't need to install a magnet. There are several legal ways to pay much less for electricity and water:
- Use LED lamps. They consume 8–10 times less electricity than conventional ones.
- Turn off the water when you are not using it. This is useful to do even in small things, such as while brushing your teeth or in the shower while you lather up.
- Always turn off the lights when leaving a room. You can install motion sensors so that the lights turn on and off automatically.
- Install aerators on taps. They break the stream into small droplets, which creates greater pressure but reduces water consumption.
- Use a washing machine and dishwasher. They use less water than hand washing or washing, and they also use cheaper cold water rather than hot water. Electricity consumption increases, but the final payment decreases.
- Fix all leaks in a timely manner.
- If the tank has one flush mode, place a bottle filled with water in it. This will slightly reduce the volume of the tank. There will still be enough water to rinse, but the consumption will decrease.
- Install a tank with two flush modes to waste less water.
- If cold water flows for a long time before hot water, you can drain it into a bucket. Then the water can be used for flushing, watering plants or other purposes.
Reasonable consumption of resources will help you save money even without magnets, so you don’t have to fear inspections and fines.
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles. Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other.
The north pole of one magnet repels the north pole of the other. The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road. For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the atom around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction.
That is, each domain is a small magnet. Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if you manage to orient the domains in one direction so that the forces of the magnetic fields combine, then beware! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Magnetic iron ore mineral is a natural magnet. But still, most magnets are made artificially. What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field.
As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet. You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large neodymium magnet.
Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Why doesn't a magnet attract everything?
In fact, the interaction of a magnet with substances has many more options than just “attracts” or “does not attract.” Iron, nickel, and some alloys are metals that, due to their specific structure, are very strongly attracted by a magnet.
The vast majority of other metals, as well as other substances, also interact with magnetic fields - they are attracted or repelled by magnets, but only thousands and millions of times weaker.
Therefore, in order to notice the attraction of such substances to a magnet, you need to use an extremely strong magnetic field, which you cannot get at home.
But since all substances are attracted to a magnet, the original question can be reformulated as follows: “Why then is iron so strongly attracted by a magnet that manifestations of this are easy to notice in everyday life?” The answer is: it is determined by the structure and bonding of iron atoms. Any substance is composed of atoms connected to each other by their outer electron shells.
It is the electrons of the outer shells that are sensitive to the magnetic field; they determine the magnetism of materials. In most substances, the electrons of neighboring atoms feel the magnetic field “at random” - some repel, others attract, and some generally try to turn the object around.
Therefore, if you take a large piece of a substance, then its average force of interaction with a magnet will be very small.
Iron and metals similar to it have a special feature - the connection between neighboring atoms is such that they sense the magnetic field in a coordinated manner. If a few atoms are tuned to be attracted to a magnet, they will cause all neighboring atoms to do the same. As a result, in a piece of iron all the atoms “want to attract” or “want to repel” at once, and because of this, a very large force of interaction with the magnet is obtained.
A magnet is a body that has its own magnetic field. In a magnetic field, there is some effect on external objects that are nearby, the most obvious being the ability of a magnet to attract metal.
The magnet and its properties were known to both the ancient Greeks and the Chinese. They noticed a strange phenomenon: small pieces of iron were attracted to some natural stones.
This phenomenon was first called divine and used in rituals, but with the development of natural science it became obvious that the properties were of a completely earthly nature, which was first explained by the physicist from Copenhagen Hans Christian Oersted.
He discovered in 1820 a certain connection between the electric discharge of current and a magnet, which gave rise to the doctrine of electric current and magnetic attraction.
Natural science research
IT News
Date Category: Physics
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Difference between neodymium magnet and ordinary magnet
The main difference between neodymium magnet and ordinary magnet is that neodymium magnet contains neodymium, iron and boron as the key chemical elements, while ordinary magnet contains iron as the main chemical element.
A neodymium magnet is a type of magnet with strong magnetism made from rare earth elements such as neodymium. It is an alloy of several metals such as iron, boron, etc. Whereas, conventional magnets are ceramic magnets which contain ferrite as the main compound. It contains a high percentage of iron(III) oxide along with some other metals such as barium. These magnets are popular due to their low cost and fairly high magnetism strength.
- Overview and main differences
- What is a neodymium magnet
- What is a regular magnet
- What is the difference between a neodymium magnet and a regular magnet
- Conclusion
What is a neodymium magnet?
How a magnet affects us: the whole truth about magnetic jewelry
Nowadays, treatment is mainly based on medications. Pharmacy shelves are filled with various tablets, capsules, syrups and drops.
In addition to their beneficial effect, they have many side effects on the body: they overload the liver and kidneys, and negatively affect the immune system. In addition, they are addictive, so when their therapeutic effect is needed most, there is no need to wait for it.
Of course, we are mainly talking about patients with chronic pathology, which requires constant monitoring and correction of the condition, and systematic use of medications.
In order to relieve the body of medications, but at the same time “keep the disease in check,” more and more doctors are trying to dilute the treatment with physiotherapy. There are many similar techniques, each with its own vectors of work. In this article we will take a closer look at magnetic therapy.
History of magnetic therapy
Why does a magnet attract - all about magnetic fields
Why does a magnet attract?
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles.
Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other. The north pole of one magnet repels the north pole of the other.
Magnetic and electric current
Neodymium magnet: what does it mean and what is it made of, how to use
Neodymium magnet is the most powerful and permanent magnet, which contains rare earth neodymium, boron and iron. What is the complete definition of a magnet and its main advantages, what is its strength and what is its principle of operation? More on this later.
What it is
Permanent magnets, their description and principle of operation:
Along with pieces of amber electrified by friction, permanent magnets were for ancient people the first material evidence of electromagnetic phenomena (lightning at the dawn of history was definitely attributed to the sphere of manifestation of immaterial forces).
Explaining the nature of ferromagnetism has always occupied the inquisitive minds of scientists, however, even now the physical nature of the permanent magnetization of some substances, both natural and artificially created, has not yet been fully revealed, leaving a considerable field of activity for modern and future researchers.
Traditional materials for permanent magnets
What metals are not magnetic and why?
Any child knows that metals are attracted to magnets. After all, they have more than once hung magnets on the metal door of the refrigerator or letters with magnets on a special board. However, if you put a spoon against a magnet, there will be no attraction. But the spoon is also metal, so why does this happen? So, let's find out which metals are not magnetic.
Scientific point of view
Why do magnets demagnetize - Metals and their processing
Employees of the site p-magnit.ru are sometimes asked about how to make a neodymium magnet with your own hands. Let's try to figure out how possible this is, and what the process of producing such products is all about.
So, the devices we sell consist of an alloy that is 70% iron and almost 30% boron. Only a fraction of a percent in its composition is made up of the rare earth metal neodymium, natural deposits of which are extremely rare in nature. Most of them are in China; they are found in only a few other countries, including Russia.
Before making neodymium magnets, manufacturers create molds for them from sand. Then the tray with the molds is doused with gas and subjected to heat treatment, due to which the sand hardens and retains the future outlines of the metal workpiece on its surface. Hot metal will later be placed in these forms, from which, in fact, the necessary products will be obtained.
Now let's directly look at how a neodymium magnet is made. Unlike ferromagnetic products, the metal here is not melted, but sintered from a powder mixture placed in an inert or vacuum environment.
Then the resulting magnetoplast is pressed while simultaneously exposing it to an electromagnetic field of a certain intensity. As you can see, even at the initial stage of production, it is noticeable that the question of how to make neodymium magnets at home sounds inappropriate.
The operations and equipment used are too complex. Creating such conditions at home is hardly possible.
After the workpieces are removed from the molds, they are subjected to mechanical processing - they are carefully polished, then they are fired to improve the coercive force of the products.
Finally, we come to the last steps, which will help to finally answer the question of how neodymium magnets are made. The sintered NdFeB alloy is again machine-finished using a special tool. During operation, a cooling lubricant is used to prevent overheating or ignition of the powder.
A protective coating is applied to the magnets. This is due, firstly, to the fact that sintered metals are quite fragile and need to be strengthened, and, secondly, the metal will be protected from corrosion processes and other environmental influences.
So manufacturers worry in advance about how to make a neodymium magnet stronger and more durable. The coating can be copper, nickel, zinc. In the last phase of the production process, magnetization is applied through a strong magnetic field.
Then they are sent to the warehouse, and from there to customers.
So, after we examined the production process in more or less detail, it became clear that we probably shouldn’t seriously ask the question “how to make a neodymium magnet at home.” After all, this requires not only certain knowledge, but many complex units.
How to completely demagnetize a neodymium magnet
Neodymium magnets are very popular in modern industry and in solving a number of everyday problems. If the buyer (for example) chose strong magnets for delivery in St. Petersburg, but violated the storage or transportation conditions, as a result of which they stuck together, it may be necessary to carry out a demagnetization procedure. The same action may be necessary in other cases when it is necessary for the product to lose its qualities.
The process can be carried out in various ways, including using factory equipment, and it is necessary to decide how to demagnetize a neodymium magnet taking into account your capabilities.
Methods for demagnetizing a magnet
Why putting a magnet on a meter is a bad idea
To reduce water and electricity bills, some people put powerful magnets on their meters. Under the influence of a magnetic field, even during the consumption of water and light, the device does not rotate.
But a magnet is not an innocent way to save money. If a person uses water and electricity, but does not pay for them, he steals, that is, he commits an administrative offense. In the laws, this is called theft and is punishable by a fine, temporary arrest or community service.
Inspectors will probably know about the magnet
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles. Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other.
The north pole of one magnet repels the north pole of the other. The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road. For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the atom around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction.
That is, each domain is a small magnet. Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if you manage to orient the domains in one direction so that the forces of the magnetic fields combine, then beware! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Magnetic iron ore mineral is a natural magnet. But still, most magnets are made artificially. What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field.
As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet. You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large neodymium magnet.
Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Why doesn't a magnet attract everything?
In fact, the interaction of a magnet with substances has many more options than just “attracts” or “does not attract.” Iron, nickel, and some alloys are metals that, due to their specific structure, are very strongly attracted by a magnet.
The vast majority of other metals, as well as other substances, also interact with magnetic fields - they are attracted or repelled by magnets, but only thousands and millions of times weaker.
Therefore, in order to notice the attraction of such substances to a magnet, you need to use an extremely strong magnetic field, which you cannot get at home.
But since all substances are attracted to a magnet, the original question can be reformulated as follows: “Why then is iron so strongly attracted by a magnet that manifestations of this are easy to notice in everyday life?” The answer is: it is determined by the structure and bonding of iron atoms. Any substance is composed of atoms connected to each other by their outer electron shells.
It is the electrons of the outer shells that are sensitive to the magnetic field; they determine the magnetism of materials. In most substances, the electrons of neighboring atoms feel the magnetic field “at random” - some repel, others attract, and some generally try to turn the object around.
Therefore, if you take a large piece of a substance, then its average force of interaction with a magnet will be very small.
Iron and metals similar to it have a special feature - the connection between neighboring atoms is such that they sense the magnetic field in a coordinated manner. If a few atoms are tuned to be attracted to a magnet, they will cause all neighboring atoms to do the same. As a result, in a piece of iron all the atoms “want to attract” or “want to repel” at once, and because of this, a very large force of interaction with the magnet is obtained.
A magnet is a body that has its own magnetic field. In a magnetic field, there is some effect on external objects that are nearby, the most obvious being the ability of a magnet to attract metal.
The magnet and its properties were known to both the ancient Greeks and the Chinese. They noticed a strange phenomenon: small pieces of iron were attracted to some natural stones.
This phenomenon was first called divine and used in rituals, but with the development of natural science it became obvious that the properties were of a completely earthly nature, which was first explained by the physicist from Copenhagen Hans Christian Oersted.
He discovered in 1820 a certain connection between the electric discharge of current and a magnet, which gave rise to the doctrine of electric current and magnetic attraction.
Natural science research
Oersted, conducting experiments with a magnetic needle and a conductor, noticed the following feature: a discharge of energy directed towards the needle instantly acted on it, and it began to deviate.
The arrow always deviated, no matter from which side he approached.
A physicist from France, Dominique François Arago, began repeated experiments with a magnet, using as a basis a glass tube rewound with a metal thread, and he installed an iron rod in the middle of this object.
With the help of electricity, the iron inside began to be sharply magnetized, because of this various keys began to stick, but as soon as the discharge was turned off, the keys immediately fell to the floor.
Based on what was happening, a physicist from France, Andre Ampere, developed an accurate description of everything that happened in this experiment.
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear. If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines). Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Magnetic effect
IT News
Date Category: Physics
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
- Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear.
- If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines).
- Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Source: https://Information-Technology.ru/sci-pop-articles/23-physics/231-pochemu-magnit-prityagivaet-zhelez
Difference between neodymium magnet and ordinary magnet
The main difference between neodymium magnet and ordinary magnet is that neodymium magnet contains neodymium, iron and boron as the key chemical elements, while ordinary magnet contains iron as the main chemical element.
A neodymium magnet is a type of magnet with strong magnetism made from rare earth elements such as neodymium. It is an alloy of several metals such as iron, boron, etc. Whereas, conventional magnets are ceramic magnets which contain ferrite as the main compound. It contains a high percentage of iron(III) oxide along with some other metals such as barium. These magnets are popular due to their low cost and fairly high magnetism strength.
- Overview and main differences
- What is a neodymium magnet
- What is a regular magnet
- What is the difference between a neodymium magnet and a regular magnet
- Conclusion
What is a neodymium magnet?
A neodymium magnet is a type of rare earth magnet that contains neodymium, iron and boron. This is a permanent magnet. It has an alloy of these metals in the form of a tetragonal crystal structure Nd2Fe14B. This magnet is the strongest commercial grade magnet currently available. Therefore, these magnets can replace many other types of magnets in modern products such as motors in cordless tools.
Neodymium is a ferromagnetic material; so we can magnetize it so that it becomes a magnet. However, the Curie temperature (the material at which a magnet loses magnetism) of this element is very low. Therefore, in its pure form it exhibits magnetism at very low temperatures. But if we make an alloy of neodymium with some transition metals such as iron, we can improve the magnetism of this material. This is a “neodymium magnet”.
Neodymium magnetic balls
There are several factors that determine the strength of this magnet. The main factor is the tetragonal crystal structure of this alloy.
In addition, the neodymium atom also has a significant magnetic dipole moment due to the presence of 4 unpaired electrons.
In addition to this, these magnets have exceptionally high residual coefficient (magnetic field strength), coercivity (material's resistance to demagnetization) and magnetic energy density. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively low.
What is a regular magnet?
Regular magnets are magnets that we use for common purposes. In most cases we use ceramic (or ferrite) magnets. These magnets contain ferrite as the main component. Ferrite is a ceramic material. It is mainly composed of iron(III) oxide. and there are also some other metals such as barium, manganese, nickel and zinc. These components are ferromagnetic and electrically non-conductive.
Ceramic magnets
In addition, these magnets have a relatively low residual magnetic induction (magnetic field strength) and coercive force (material resistance to demagnetization). But there are two types of ferrite magnets: hard ferrites and soft ferrites depending on the coercivity (high and low respectively). The magnetic energy density is also very low. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively high.
Source: https://raznisa.ru/raznica-mezhdu-neodimovym-magnitom-i-obychnym-magnitom/
How a magnet affects us: the whole truth about magnetic jewelry
Nowadays, treatment is mainly based on medications. Pharmacy shelves are filled with various tablets, capsules, syrups and drops.
In addition to their beneficial effect, they have many side effects on the body: they overload the liver and kidneys, and negatively affect the immune system. In addition, they are addictive, so when their therapeutic effect is needed most, there is no need to wait for it.
Of course, we are mainly talking about patients with chronic pathology, which requires constant monitoring and correction of the condition, and systematic use of medications.
In order to relieve the body of medications, but at the same time “keep the disease in check,” more and more doctors are trying to dilute the treatment with physiotherapy. There are many similar techniques, each with its own vectors of work. In this article we will take a closer look at magnetic therapy.
History of magnetic therapy
Magnetotherapy is a physiotherapeutic technique based on the effect of a magnetic field on the human body.
Since ancient times, people have been interested in magnetic fields. Their existence was first noticed about 2 thousand years ago. Over time, it found practical application in the form of a compass. According to historical documents, it was first noticed in China 1 thousand years before the new era that a long piece of magnetic iron attached to a plug floating in a liquid pointed north.
Since then, people began to find new uses for this important invention. Without it, it would have been impossible to create cars, ships, tape recorders, etc. In medicine, the magnet also played an undeniable role.
Doctors of ancient times (immediately after the discovery of the properties of a magnet) began to study its effect on the human body. Initially, data on its properties for humans were contradictory. Some considered the magnet a potent poison, while others considered it a panacea. The history of medicine knows many cases of the use of magnets as a remedy:
- Hippocrates used magnetic powder as a laxative.
- Cleopatra constantly wore a magnetic necklace, which was supposed to preserve her beauty and youth.
- Queen Elizabeth I suffered from arthritis. According to the documents, she was treated with magnets.
- Franz Antoine Mesmer cured many people using magnets. He successfully practiced in Vienna and Paris, where, as part of the team of the Royal Society of Medicine, he tried to use this technique to heal people with seizures and nervous diseases. They used magnets in the form of rings, bracelets, and amulets. After conducting many experiments, Mesmer came to the conclusion that our body is surrounded by a magnetic field, and direct influence on it can help cure many diseases.
- After the Civil War, there was a real shortage of qualified medical personnel in the United States. This led to the spread of folk remedies. Magnets were especially popular. They were used in the form of insoles, bandages, and rings. They have been successfully used as a pain reliever.
- At the beginning of the 19th century, more and more articles began to appear scientifically substantiating the use of magnetic therapy.
Nowadays, this type of physiotherapy has become especially widespread in the USA, China, and Japan. Many means, methods and types of magnetic therapy have been developed, which are successfully used in various branches of medicine.
Scientific rationale for magnetic therapy
How and why does it work? How can a small bracelet help you cure a huge list of diseases?
Thanks to physics, we know that everything in the world has its own magnetic fields. Man is no exception. Our magnetic field is formed due to the flow of blood through the vessels. It consists of metal ions, which, when circulating, form a static magnetic field. It is present where there are blood vessels in our body, that is, absolutely everywhere.
When we are exposed to a magnetic field, electric currents are generated in the body. Because of this, a number of changes occur:
- changes in the configuration of cell membranes and their structural units (lysosomes, mitochondria, etc.);
- changes in cell membrane permeability;
- changes in the course of chemical reactions in the body that occur with the participation of free radicals (almost all processes in which enzymes are involved);
- changes in the physicochemical properties of all body fluids;
- reorientation of large molecules (including proteins, fats, carbohydrates).
By influencing these basic processes in the body, you can regulate its condition. Currently, many studies have been conducted that confirm the effectiveness of magnetic therapy. They make it possible to become an alternative to heavy medication load.
Types of magnetic therapy
Thanks to technological progress, several types of magnets are available to us that can be used for therapeutic purposes. Magnetic therapy is differentiated based on the type of magnetic fields: variable and constant. There is also a distinction between general magnetic therapy (when the effect occurs on the entire body as a whole) and local (the effect is carried out locally: on a joint, a separate organ or area).
If we talk about technical equipment, there are now three main types of devices available:
- Stationary. It consists of a table, a magnet and a computer, which contains several basic treatment protocols. The patient lies down on the table, and the physiotherapist selects the necessary protocol. The device can also be equipped with additional components (a magnet for local, directional influence, a belt, a solenoid that allows you to create a circular magnetic field). Treatment usually takes place in courses. One session lasts from 15 to 40 minutes. No special preparation is required. The only recommendation is to drink a glass of water before the procedure to slightly enhance the effect of the device.
- Portable. It is a device that the patient can easily carry with him. The effect is carried out by applying the device to the affected area of the body or wearing it in this area. The most popular device is considered to be “Magofon-01”, which creates special vibroacoustic vibrations and a low-frequency magnetic field. This type of device has pronounced analgesic, anti-edematous and anti-inflammatory effects.
- Magnetic jewelry. Patients wishing to purchase magnetic jewelry have a wide range of choices: rings, bracelets, necklaces, watches, earrings, brooches, etc. They are often elegantly and tastefully made. Naturally, it is difficult to suspect a medicinal product in these accessories. They are usually made of copper, metal, or jewelry steel. Active magnets are placed on their inner surface. It is the latter that have a special field; accordingly, they are made with extreme care in order to help and not harm a person.
The impact of magnetic jewelry on the human body
Magnets change our state at the molecular level. This affects the organs and their performance, which allows doctors to recommend them as an additional treatment for a number of pathologies.
The main beneficial therapeutic effects of magnetic jewelry include:
- Improving microcirculation. Blood circulation under the influence of magnetic fields improves throughout the body, including blood circulation in the brain. This effect is realized due to an increase in the lumen of the smallest vessels in our body - capillaries. At the same time, the speed of blood flow in vessels of medium and large caliber is optimized.
- Reduced blood viscosity. This effect helps prevent the formation of blood clots.
- Improving the permeability of the vascular wall. It also optimizes blood flow while slowly clearing cholesterol deposits from the blood vessels.
- Normalization of lymphatic drainage. Magnetic fields have a beneficial effect on lymphatic vessels, expanding their lumen. This promotes better lymph outflow, reducing tissue swelling and accelerating the process of removing by-products of metabolic processes.
- Stimulation of tissue nutrition. This implies that tissues begin to receive more nutrients when using magnetic jewelry. Metabolism at the cellular level is enhanced, which improves recovery and regeneration processes in the body.
- Anti-inflammatory effect. Reducing swelling, improving blood circulation in organs and optimizing the synthesis of anti-inflammatory substances (prostaglandins) contributes to a faster resolution of inflammatory processes in the body.
- Regulation of the nervous system. This technique allows you to activate the processes of excitation or inhibition of the nervous system, depending on the type of magnetic therapy and the point of application.
- Decreased sensitivity of pain receptors. The impact on this type of receptor allows magnetic jewelry to realize an analgesic effect. In addition, there are studies that clearly demonstrate that magnetic fields can lead to the regeneration of nerve fibers and improve the conduction of impulses through them.
For what diseases are magnetic jewelry recommended?
Considering these effects of magnetic jewelry, it is advisable to use them for diseases such as:
Pathology of the cardiovascular system |
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Pathology of the nervous system |
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Diseases of the bronchopulmonary system and ENT organs |
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Diseases of the musculoskeletal system |
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Diseases of the gastrointestinal tract |
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Pathology of the urinary and reproductive system |
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Oral diseases |
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Pathologies of the visual analyzer |
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Skin diseases |
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Endocrine system |
|
Source: https://fitexpert.biz/magnity/
Why does a magnet attract - all about magnetic fields
Why does a magnet attract?
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles.
Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other. The north pole of one magnet repels the north pole of the other.
Magnetic and electric current
The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
Magnetic field lines
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road.
For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
Related materials:
Gravitational interaction
Electron movement and magnetic field
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the electron around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
Why materials are magnetic and not magnetic
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction. That is, each domain is a small magnet.
Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if we manage to orient the domains in one direction so that the forces of the magnetic fields add up, then watch out! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Interesting fact: the mineral iron ore is a natural magnet. But still, most magnets are made artificially.
What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field. As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet.
Related materials:
How are magnets made?
You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large horseshoe magnet. Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Source: https://kipmu.ru/pochemu-magnit-prityagivaet-ili-vse-o-magnitnyx-polyax/
Neodymium magnet: what does it mean and what is it made of, how to use
Neodymium magnet is the most powerful and permanent magnet, which contains rare earth neodymium, boron and iron. What is the complete definition of a magnet and its main advantages, what is its strength and what is its principle of operation? More on this later.
What it is
A neodymium magnet is a magnetic element that is composed of neodymium rare earth boron and iron material. It has a crystal structure, tetragonal shape and formula Nd2Fe14B.
Neodymium magnet is the most common type
It was first created by General Motors in 1982. It is the strongest permanent magnetic element, the power of which is several times greater than usual. Equipped with a large magnetic induction of 12,400 gauss.
Note! This is a brittle alloy with the formula NdFeB, as well as a hard nickel-plated protective layer and the corresponding class. It is very popular and comes in various forms.
Full material definition
Advantages
The most common neodymium magnet is one that has an iron oxide alloy, which has good heat resistance, high magnetic permeability and low cost. Equipped with color coding, high coercivity, powerful magnetic field to hold objects suspended, compact size, light weight, affordable and wide range of applications. Has a long service life.
If an ordinary magnet works for 10 years and can be demagnetized, then a neodymium magnet does not lose its properties after 100 years. Another advantage is the shape. This product has a horseshoe shape. It gives the device a long service life. As for the cost, these are expensive products, but the cost is justified by excellent performance and impeccable reliability.
Durability of work as one of the advantages
Force
It is worth pointing out that the strength contained in neodymium magnets is another advantage. She is tall and it is impossible to find a competitor to her. This is a record type of indicator, the increase of which is impossible. Power is generated during manufacturing. Magnetization occurs after the alloy is formed. Thanks to existing technologies, the alloy is magnetized in such a way that the magnet has incredibly high power and this figure reaches a record.
Note! Power is a relative philistine concept. The force is stable, but it is measured using instruments. In this case, the readings depend on the thickness of the surface and cleanliness. The separation angle can have some influence.
Strength as one of the advantages
Life time
The service life of the equipment, if used properly, is 30 years. Due to careless handling, the device may be damaged. The point is the lack of flexibility, as well as brittleness and cracking under heavy load. Falls, impacts, or reduced traction will reduce the life of the equipment. For this reason, it is necessary to avoid falls using parts that come into contact during movements.
Another extremely important point is the irreversible loss of magnetic properties due to heating. Therefore, grinding with cutting or drilling reduces the chain force and may ignite the alloy. If storage and operation are organized correctly, then magnetization is maintained for 10 years.
Long service life
Design
When answering the question of what a neodymium magnet is made of, we can point out that it is a rare earth element that contains an atom with lanthanide or actinide. The classic composition may still contain an additive.
It is used to increase strength with endurance and resistance to high temperatures. Boron is used in small quantities, iron is a binding element. Thanks to this composition, greater adhesion is obtained.
When connecting several ferrite rings, you can separate them with your hands. As for neodymium magnets, this cannot be done.
Composition of magnetic material
How are neodymium magnets magnetized?
The magnetization of neodymium magnets occurs through the interaction of bromine ions, iron and neodymium in a powerful magnetic field. Thanks to such actions, an element is obtained that has a high coercive force and high adhesion power. It also has an extremely long service life in everyday life.
Magnetization of neodymium materials
Principle of operation
A neodymium magnet works very simply. If two magnetic elements are connected and the poles coincide in direction, the magnetic force of the two fields will be enhanced. The result is an overall strong magnetic field. With the reverse arrangement of the magnetized elements, the magnetic field will be suppressed.
Principle of operation
How to use
Neodymium magnetic element is the strongest, exceeding analogues that are based on rare earth metal. In addition, neodymium is capable of maintaining a magnetized structure for a significantly long time. Such equipment can be used in various fields. For example, it is used in the manufacture of over-ear headphones with wind generators, motor wheels and scooters.
Note! Magnets are actively used in industrial, household, and medical fields. They are also used to carry out search work with a metal detector. They can often be found in plumbing fixtures or souvenirs.
Specific examples include the use of magnets in the development of medical devices, magnetic treatment of water, the creation of oil and technological filters, and the formation of actuators with highly sensitive sensors. In addition, they are needed to produce clothes with covers and shoes, and to create advertising, information and navigation materials.
Scope of application of the material
Overall, neodymium is the most powerful permanent magnetic material that has high resistance to demagnetization, attractive power, and a metallic appearance. It has a long service life and consists of boron, iron and a metal of the lanthanide group.
Source: https://rusenergetics.ru/polezno-znat/neodimovykh-magnitakh
Permanent magnets, their description and principle of operation:
Along with pieces of amber electrified by friction, permanent magnets were for ancient people the first material evidence of electromagnetic phenomena (lightning at the dawn of history was definitely attributed to the sphere of manifestation of immaterial forces).
Explaining the nature of ferromagnetism has always occupied the inquisitive minds of scientists, however, even now the physical nature of the permanent magnetization of some substances, both natural and artificially created, has not yet been fully revealed, leaving a considerable field of activity for modern and future researchers.
Traditional materials for permanent magnets
They have been actively used in industry since 1940 with the advent of alnico alloy (AlNiCo). Previously, permanent magnets made of various types of steel were used only in compasses and magnetos. Alnico made it possible to replace electromagnets with them and use them in devices such as motors, generators and loudspeakers.
This penetration into our daily lives received a new impetus with the creation of ferrite magnets, and since then permanent magnets have become commonplace.
The revolution in magnetic materials began around 1970, with the creation of the samarium-cobalt family of hard magnetic materials with previously unheard-of magnetic energy densities.
Then a new generation of rare earth magnets was discovered, based on neodymium, iron and boron, with a much higher magnetic energy density than samarium cobalt (SmCo) and at an expectedly low cost.
These two families of rare earth magnets have such high energy densities that they can not only replace electromagnets, but be used in areas that are inaccessible to them. Examples include the tiny permanent magnet stepper motor in wristwatches and the sound transducers in Walkman-type headphones.
The gradual improvement in the magnetic properties of materials is shown in the diagram below.
Neodymium permanent magnets
They represent the latest and most significant development in this field over the past decades. Their discovery was first announced almost simultaneously at the end of 1983 by metal specialists from Sumitomo and General Motors. They are based on the intermetallic compound NdFeB: an alloy of neodymium, iron and boron. Of these, neodymium is a rare earth element extracted from the mineral monazite.
The enormous interest that these permanent magnets have generated arises because for the first time a new magnetic material has been produced that is not only stronger than the previous generation, but is more economical.
It consists mainly of iron, which is much cheaper than cobalt, and neodymium, which is one of the most common rare earth materials and has more reserves on Earth than lead.
The major rare earth minerals monazite and bastanesite contain five to ten times more neodymium than samarium.
Physical mechanism of permanent magnetization
To explain the functioning of a permanent magnet, we must look inside it down to the atomic scale. Each atom has a set of spins of its electrons, which together form its magnetic moment.
For our purposes, we can consider each atom as a small bar magnet. When a permanent magnet is demagnetized (either by heating it to a high temperature or by an external magnetic field), each atomic moment is oriented randomly (see Fig.
below) and no regularity is observed.
When it is magnetized in a strong magnetic field, all atomic moments are oriented in the direction of the field and, as it were, interlocked with each other (see figure below). This coupling allows the permanent magnet field to be maintained when the external field is removed, and also resists demagnetization when its direction is changed. A measure of the cohesive force of atomic moments is the magnitude of the coercive force of the magnet. More on this later.
In a more in-depth presentation of the magnetization mechanism, one does not operate with the concepts of atomic moments, but uses ideas about miniature (of the order of 0.001 cm) regions inside the magnet, which initially have permanent magnetization, but are randomly oriented in the absence of an external field, so that a strict reader, if desired, can attribute the above physical The mechanism is not related to the magnet as a whole. but to its separate domain.
Induction and magnetization
The atomic moments are summed up and form the magnetic moment of the entire permanent magnet, and its magnetization M shows the magnitude of this moment per unit volume. Magnetic induction B shows that a permanent magnet is the result of an external magnetic force (field strength) H applied during primary magnetization, as well as an internal magnetization M due to the orientation of atomic (or domain) moments. Its value in the general case is given by the formula:
B = µ0 (H + M),
where µ0 is a constant.
In a permanent ring and homogeneous magnet, the field strength H inside it (in the absence of an external field) is equal to zero, since, according to the law of total current, the integral of it along any circle inside such a ring core is equal to:
H∙2πR = iw=0, whence H=0.
Therefore, the magnetization in a ring magnet is:
M = B/µ0.
In an open magnet, for example, in the same ring magnet, but with an air gap of width lzaz in a core of length lser, in the absence of an external field and the same induction B inside the core and in the gap, according to the law of total current, we obtain:
Hser l ser + (1/ µ0)Blzaz = iw=0.
Since B = µ0(Hser + Mser), then, substituting its expression into the previous one, we get:
Hser(l ser + lzaz) + Mser lzaz=0,
or
Hser = ─ Mser lzaz(l ser + lzaz).
In the air gap:
Hzaz = B/µ0,
wherein B is determined by the given Mser and the found Hser.
Magnetization curve
Starting from the unmagnetized state, when H increases from zero, due to the orientation of all atomic moments in the direction of the external field, M and B quickly increase, changing along section “a” of the main magnetization curve (see figure below).
When all atomic moments are equalized, M comes to its saturation value, and a further increase in B occurs solely due to the applied field (section b of the main curve in the figure below).
When the external field decreases to zero, the induction B decreases not along the original path, but along section “c” due to the coupling of atomic moments, tending to maintain them in the same direction. The magnetization curve begins to describe the so-called hysteresis loop.
When H (external field) approaches zero, the induction approaches a residual value determined only by atomic moments:
Br = μ0 (0 + Mg).
After the direction of H changes, H and M act in opposite directions and B decreases (part of the curve “d” in the figure). The value of the field at which B decreases to zero is called the coercive force of the BHC magnet.
When the magnitude of the applied field is large enough to break the cohesion of the atomic moments, they are oriented in the new direction of the field, and the direction of M is reversed. The field value at which this occurs is called the internal coercive force of the permanent magnet MHC.
So, there are two different but related coercive forces associated with a permanent magnet.
The figure below shows the basic demagnetization curves of various materials for permanent magnets. It shows that NdFeB magnets have the highest residual induction Br and coercive force (both total and internal, i.e., determined without taking into account the strength H, only by the magnetization M).
Surface (ampere) currents
The magnetic fields of permanent magnets can be considered as the fields of some associated currents flowing along their surfaces. These currents are called Ampere currents. In the usual sense of the word, there are no currents inside permanent magnets.
However, comparing the magnetic fields of permanent magnets and the fields of currents in coils, the French physicist Ampere suggested that the magnetization of a substance can be explained by the flow of microscopic currents, forming microscopic closed circuits.
And indeed, the analogy between the field of a solenoid and a long cylindrical magnet is almost complete: there is a north and south pole of a permanent magnet and the same poles of the solenoid, and the patterns of force lines of their fields are also very similar (see figure below).
Are there currents inside a magnet?
Let's imagine that the entire volume of a bar permanent magnet (with an arbitrary cross-sectional shape) is filled with microscopic Ampere currents. A cross section of a magnet with such currents is shown in the figure below. Each of them has a magnetic moment. With the same orientation in the direction of the external field, they form a resulting magnetic moment that is different from zero.
It determines the existence of a magnetic field in the apparent absence of ordered movement of charges, in the absence of current through any cross section of the magnet. It is also easy to understand that inside it, the currents of adjacent (contacting) circuits are compensated. Only the currents on the surface of the body, which form the surface current of a permanent magnet, are uncompensated.
Its density turns out to be equal to the magnetization M.
How to get rid of moving contacts
The problem of creating a contactless synchronous machine is known. Its traditional design with electromagnetic excitation from the poles of a rotor with coils involves supplying current to them through movable contacts - slip rings with brushes.
The disadvantages of such a technical solution are well known: they are difficulties in maintenance, low reliability, and large losses in moving contacts, especially when it comes to powerful turbo and hydrogen generators, the excitation circuits of which consume considerable electrical power.
If you make such a generator using permanent magnets, then the contact problem immediately goes away. However, there is a problem of reliable fastening of magnets on a rotating rotor. This is where the experience gained in tractor manufacturing can come in handy. They have long been using an inductor generator with permanent magnets located in rotor slots filled with a low-melting alloy.
Permanent magnet motor
In recent decades, DC motors have become widespread. Such a unit consists of the electric motor itself and an electronic commutator for its armature winding, which performs the functions of a collector.
The electric motor is a synchronous motor with permanent magnets located on the rotor, as in Fig. above, with a stationary armature winding on the stator.
Electronic switch circuitry is an inverter of direct voltage (or current) of the supply network.
The main advantage of such a motor is its non-contact nature. Its specific element is a photo-, induction or Hall rotor position sensor that controls the operation of the inverter.
Source: https://syl.ru/article/203617/new_postoyannyie-magnityi-ih-opisanie-i-printsip-deystviya
What metals are not magnetic and why?
Any child knows that metals are attracted to magnets. After all, they have more than once hung magnets on the metal door of the refrigerator or letters with magnets on a special board. However, if you put a spoon against a magnet, there will be no attraction. But the spoon is also metal, so why does this happen? So, let's find out which metals are not magnetic.
Scientific point of view
To determine which metals are not magnetic, you need to find out how all metals in general can relate to magnets and a magnetic field. With respect to the applied magnetic field, all substances are divided into diamagnetic, paramagnetic and ferromagnetic.
Each atom consists of a positively charged nucleus and negatively charged electrons. They move continuously, which creates a magnetic field. The magnetic fields of electrons in one atom can enhance or cancel each other, depending on the direction of their movement. Moreover, the following can be compensated:
- Magnetic moments caused by the movement of electrons relative to the nucleus are orbital.
- Magnetic moments caused by the rotation of electrons around their axis are spin moments.
If all magnetic moments are equal to zero, the substance is classified as diamagnetic. If only spin moments are compensated - to paramagnets. If the fields are not compensated, use ferromagnets.
Paramagnets and ferromagnets
Let's consider the option when each atom of a substance has its own magnetic field. These fields are multidirectional and compensate each other. If you place a magnet next to such a substance, the fields will be oriented in one direction. The substance will have a magnetic field, a positive and a negative pole.
Then the substance will be attracted to the magnet and can itself become magnetized, that is, it will attract other metal objects. For example, you can magnetize steel clips at home. Each one will have a negative and a positive pole, and you can even hang a whole chain of paper clips on a magnet.
Such substances are called paramagnetic.
Ferromagnets are a small group of substances that are attracted to magnets and are easily magnetized even in a weak field.
Diamagnets
In diamagnetic materials, the magnetic fields inside each atom are compensated. In this case, when a substance is introduced into a magnetic field, the movement of electrons under the influence of the field will be added to the natural movement of electrons. This movement of electrons will cause an additional current, the magnetic field of which will be directed against the external field. Therefore, the diamagnetic material will be weakly repelled from the nearby magnet.
So, if we approach the question from a scientific point of view, which metals are not magnetic, the answer will be – diamagnetic.
Distribution of paramagnets and diamagnets in the periodic table of Mendeleev elements
The magnetic properties of simple substances change periodically with increasing atomic number of the element.
Substances that are not attracted to magnets (diamagnets) are located mainly in short periods - 1, 2, 3. Which metals are not magnetic? These are lithium and beryllium, and sodium, magnesium and aluminum are already classified as paramagnetic.
Substances that are attracted to magnets (paramagnets) are located mainly in the long periods of the Mendeleev periodic system - 4, 5, 6, 7.
However, the last 8 elements in each long period are also diamagnetic.
In addition, three elements are distinguished - carbon, oxygen and tin, the magnetic properties of which are different for different allotropic modifications.
In addition, there are 25 more chemical elements whose magnetic properties could not be established due to their radioactivity and rapid decay or the complexity of synthesis.
The magnetic properties of lanthanides and actinides (all of which are metals) change irregularly. Among them there are para- and diamagnetic materials.
There are special magnetically ordered substances - chromium, manganese, iron, cobalt, nickel, the properties of which change irregularly.
What metals are not magnetic: list
There are only 9 ferromagnets, that is, metals that are highly magnetic, in nature. These are iron, cobalt, nickel, their alloys and compounds, as well as six lanthanide metals: gadolinium, terbium, dysprosium, holmium, erbium and thulium.
Metals that are attracted only to very strong magnets (paramagnetic): aluminum, copper, platinum, uranium.
Since in everyday life there are no such large magnets that would attract a paramagnetic material, and also no lanthanide metals are found, we can safely say that all metals except iron, cobalt, nickel and their alloys will not be attracted to magnets.
So, what metals are not magnetic to a magnet:
- paramagnetic materials: aluminum, platinum, chromium, magnesium, tungsten;
- diamagnetic materials: copper, gold, silver, zinc, mercury, cadmium, zirconium.
In general, we can say that ferrous metals are attracted to a magnet, non-ferrous metals are not.
If we talk about alloys, then iron alloys are magnetic. These primarily include steel and cast iron. Precious coins can also be attracted to a magnet, since they are not made of pure non-ferrous metal, but of an alloy that may contain a small amount of ferromagnetic material. But jewelry made of pure non-ferrous metal will not be attracted to a magnet.
What metals do not rust and are not magnetic? These are ordinary food grade stainless steel, gold and silver items.
Source: https://FB.ru/article/435941/kakie-metallyi-ne-magnityatsya-i-pochemu
Why do magnets demagnetize - Metals and their processing
Employees of the site p-magnit.ru are sometimes asked about how to make a neodymium magnet with your own hands. Let's try to figure out how possible this is, and what the process of producing such products is all about.
So, the devices we sell consist of an alloy that is 70% iron and almost 30% boron. Only a fraction of a percent in its composition is made up of the rare earth metal neodymium, natural deposits of which are extremely rare in nature. Most of them are in China; they are found in only a few other countries, including Russia.
Before making neodymium magnets, manufacturers create molds for them from sand. Then the tray with the molds is doused with gas and subjected to heat treatment, due to which the sand hardens and retains the future outlines of the metal workpiece on its surface. Hot metal will later be placed in these forms, from which, in fact, the necessary products will be obtained.
Now let's directly look at how a neodymium magnet is made. Unlike ferromagnetic products, the metal here is not melted, but sintered from a powder mixture placed in an inert or vacuum environment.
Then the resulting magnetoplast is pressed while simultaneously exposing it to an electromagnetic field of a certain intensity. As you can see, even at the initial stage of production, it is noticeable that the question of how to make neodymium magnets at home sounds inappropriate.
The operations and equipment used are too complex. Creating such conditions at home is hardly possible.
After the workpieces are removed from the molds, they are subjected to mechanical processing - they are carefully polished, then they are fired to improve the coercive force of the products.
Finally, we come to the last steps, which will help to finally answer the question of how neodymium magnets are made. The sintered NdFeB alloy is again machine-finished using a special tool. During operation, a cooling lubricant is used to prevent overheating or ignition of the powder.
A protective coating is applied to the magnets. This is due, firstly, to the fact that sintered metals are quite fragile and need to be strengthened, and, secondly, the metal will be protected from corrosion processes and other environmental influences.
So manufacturers worry in advance about how to make a neodymium magnet stronger and more durable. The coating can be copper, nickel, zinc. In the last phase of the production process, magnetization is applied through a strong magnetic field.
Then they are sent to the warehouse, and from there to customers.
So, after we examined the production process in more or less detail, it became clear that we probably shouldn’t seriously ask the question “how to make a neodymium magnet at home.” After all, this requires not only certain knowledge, but many complex units.
How to completely demagnetize a neodymium magnet
Neodymium magnets are very popular in modern industry and in solving a number of everyday problems. If the buyer (for example) chose strong magnets for delivery in St. Petersburg, but violated the storage or transportation conditions, as a result of which they stuck together, it may be necessary to carry out a demagnetization procedure. The same action may be necessary in other cases when it is necessary for the product to lose its qualities.
The process can be carried out in various ways, including using factory equipment, and it is necessary to decide how to demagnetize a neodymium magnet taking into account your capabilities.
Methods for demagnetizing a magnet
Loss of the ability to attract metal objects can occur both naturally and during a number of actions. Subject to the rules of operation and storage, the qualities of neodymium elements are maintained for 100 years or more, and ferrite analogues continue to attract metal for 8-10 years. Degaussing neodymiums naturally is not practical if the procedure is to be performed on a new item.
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Product heating
This method is used both in industrial and domestic conditions: if the magnet is made of a standard alloy of neodymium with boron and iron, it will lose its properties when placed in water boiling at 80 degrees Celsius or in case of contact with a surface heated to the specified temperature.
If we are talking about a product with increased resistance to thermal shocks, it is unlikely that it will be possible to perform the procedure at home: the demagnetization temperature of neodymium magnets with such properties is 200 degrees Celsius.
To carry out the procedure in such cases, special industrial equipment is used.
Mechanical Actions
Neodymium can lose its qualities as a result of a strong directed impact, for example, an impact: this material has a powder structure that is destroyed when dropped from a height or when exposed to impact equipment. In addition, demagnetization can occur accidentally during the process of drilling or cutting a magnet: this is due to excessive mechanical pressure or an increase in the temperature of the product without forced cooling.
Treatment with external magnetic influence
Most often, if it is possible to use industrial equipment of increased power, another magnet is used, which allows the formation of a field with an induction force of about 4 Tesla. A neodymium magnet is demagnetized in a matter of seconds, so this method, despite its technological complexity, is characterized by the fastest possible result.
How to magnetize demagnetized neodymium
If the demagnetization of an element occurs accidentally, and it is necessary to return the product to its properties, it is impossible to do this at home. Restoring a neodymium magnet requires the use of a product that can create a very powerful field, and this requires the use of professional equipment used to create such items.
Usually, if you need to return the magnetization properties for a specific element, you contact a factory that specializes in the production of such products.
Is there anything I can do to make the magnet stronger?
If neodymium used for household purposes has become demagnetized, often a more appropriate solution would be to purchase a new element. The cost of magnetization work varies depending on the required properties and pricing policy of a particular production.
Application of neodymium magnet
These products are available in various shapes and sizes and are used for the following tasks:
- Creating a clamping effect, fixing metal elements to each other. Using neodymium magnets, you can attach an antenna, license plate, plate, other metal part, device or entire mechanism.
- Filtration of oil systems in cars and other equipment: neodymium magnets allow you to easily and quickly remove metal shavings.
- Creation of magnetic locks and fasteners used in industrial sectors and household purposes.
- Search work related to the search for metal objects (search for treasures, historical values, weapons, mine clearance work, etc.).
- Restoring other magnetic elements: using a neodymium element, you can create a magnetic field that will return the product to its ability to attract metal.
- Deleting information recorded on floppy disks, disks, flash drives and other electronic media for security purposes.
- Creation of devices for universal use (hangers, stirring devices, compasses, etc.).
- Construction of current generators that can be used as experimental models or devices suitable for domestic use.
- Making jewelry: Neodymium can come in different shapes and sizes, and beads made from this material are often given a chrome finish and can be painted in different colors.
- Treatment of water using magnetic influence, as a result of which the formation of scale is reduced, and the liquid itself acquires an improved taste and smell.
- Fuel conditioning, which allows you to reduce fuel consumption for cars and motorcycles.
- Sorting small metal items that need to be removed from a variety of non-metal items.
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Conclusion
Neodymium magnets are products that are widely used in commercial, industrial and household applications, they are characterized by high load capacity, excellent attractive properties and durability.
Before demagnetizing neodymium magnets, it is important to make sure that you have the necessary equipment: this requires either an industrial installation or a device for heating to at least 80 degrees.
Magnetizing products that have lost their quality is rarely advisable, but if necessary, you can order the procedure by contacting the manufacturer.
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Source: https://magnetline.ru/metally-i-splavy/pochemu-magnity-razmagnichivayutsya.html
Why putting a magnet on a meter is a bad idea
To reduce water and electricity bills, some people put powerful magnets on their meters. Under the influence of a magnetic field, even during the consumption of water and light, the device does not rotate.
But a magnet is not an innocent way to save money. If a person uses water and electricity, but does not pay for them, he steals, that is, he commits an administrative offense. In the laws, this is called theft and is punishable by a fine, temporary arrest or community service.
Inspectors will probably know about the magnet
It seems that if you install a magnet only occasionally and pay a little on the bills, then no one will know about the violation. But inspectors have several ways to detect theft:
- See the magnet. Usually they try not to let the inspectors in or quickly remove the magnet before opening the doors. But it may happen that the person who placed it will not be at home, the door will be opened by a child or a grandmother who has come to stay, or the residents will simply forget about the magnet. Then the inspector will take a photo of the violation and draw up a report, and then you will be issued a fine.
- Check the indicator. Modern water and light meters have special indicators, or magnetic field sensors. It is enough to bring a powerful magnet to the meter once - and the indicator will change color forever. And some of the most modern devices can even send a message to the dispatcher, so they will instantly know about the magnet.
- Measure the magnetic field. If a magnet has recently been placed on the meter, the magnetic field around it will be abnormally large. It can be measured using a special device - a Teslameter. And if the indicator can sometimes somehow be fooled, then the Teslameter cannot be fooled: it will clearly indicate that there was a magnet on the meter.
The Teslameter is expensive and is still rarely used, but gradually this method is becoming more and more popular. You can especially often find inspectors with teslameters in Moscow and St. Petersburg.
To record a violation and draw up a report, inspectors must come to the meter in person. To do this, management companies (MCs) arrange scheduled inspections every 1–2 years. Theoretically, you can adapt to them and use the magnet only immediately after the inspectors’ visit in order to save at least a little.
But if according to the general building meter the resource consumption is the same, but according to the sum of the apartment meters it is significantly less, this indicates theft on the part of the residents. In this case, the management company can arrange an unscheduled inspection and detect the magnet.
You will be punished for installing a magnet
Most often, on the basis of Government Resolution No. 354, they are required to pay the cost of resources tenfold. The cost is calculated according to average standards and multiplied by the time that has passed since the last inspection, but by a maximum of 3 months.
That is, if you install a magnet and it is discovered in six months, you will be forced to pay 10 times more than you would pay according to the standards for three months. Standards, by the way, are often too high.
Usually people spend less than the average per month, so the overpayment will be large.
This fine is not related to theft - it only relates to violation of the meter. If the Criminal Code decides to sue, the violator faces the following penalties:
- A fine of 10–15 thousand rubles for the unauthorized use of electrical, thermal energy, oil or gas, according to the Administrative Code.
- A fine of five times the value of the stolen property for petty theft up to 1 thousand rubles, according to the Administrative Code.
- A fine for petty theft is from 1 to 2.5 thousand rubles in the amount of five times the value of the stolen property, or arrest for 10–15 days, or up to 120 hours of community service.
Theoretically, when more than 2.5 thousand rubles are stolen, the crime is no longer considered administrative, but criminal. He faces a fine of up to 300 thousand rubles or imprisonment for 1–2 years. But in fact, such punishments are not imposed in the Russian Federation for magnets on meters.
You can save money without a magnet
To save money, you don't need to install a magnet. There are several legal ways to pay much less for electricity and water:
- Use LED lamps. They consume 8–10 times less electricity than conventional ones.
- Turn off the water when you are not using it. This is useful to do even in small things, such as while brushing your teeth or in the shower while you lather up.
- Always turn off the lights when leaving a room. You can install motion sensors so that the lights turn on and off automatically.
- Install aerators on taps. They break the stream into small droplets, which creates greater pressure but reduces water consumption.
- Use a washing machine and dishwasher. They use less water than hand washing or washing, and they also use cheaper cold water rather than hot water. Electricity consumption increases, but the final payment decreases.
- Fix all leaks in a timely manner.
- If the tank has one flush mode, place a bottle filled with water in it. This will slightly reduce the volume of the tank. There will still be enough water to rinse, but the consumption will decrease.
- Install a tank with two flush modes to waste less water.
- If cold water flows for a long time before hot water, you can drain it into a bucket. Then the water can be used for flushing, watering plants or other purposes.
Reasonable consumption of resources will help you save money even without magnets, so you don’t have to fear inspections and fines.
Source: https://Lifehacker.ru/magnit-na-schyotchik/
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles. Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other.
The north pole of one magnet repels the north pole of the other. The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road. For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the atom around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction.
That is, each domain is a small magnet. Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if you manage to orient the domains in one direction so that the forces of the magnetic fields combine, then beware! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Magnetic iron ore mineral is a natural magnet. But still, most magnets are made artificially. What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field.
As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet. You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large neodymium magnet.
Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Why doesn't a magnet attract everything?
In fact, the interaction of a magnet with substances has many more options than just “attracts” or “does not attract.” Iron, nickel, and some alloys are metals that, due to their specific structure, are very strongly attracted by a magnet.
The vast majority of other metals, as well as other substances, also interact with magnetic fields - they are attracted or repelled by magnets, but only thousands and millions of times weaker.
Therefore, in order to notice the attraction of such substances to a magnet, you need to use an extremely strong magnetic field, which you cannot get at home.
But since all substances are attracted to a magnet, the original question can be reformulated as follows: “Why then is iron so strongly attracted by a magnet that manifestations of this are easy to notice in everyday life?” The answer is: it is determined by the structure and bonding of iron atoms. Any substance is composed of atoms connected to each other by their outer electron shells.
It is the electrons of the outer shells that are sensitive to the magnetic field; they determine the magnetism of materials. In most substances, the electrons of neighboring atoms feel the magnetic field “at random” - some repel, others attract, and some generally try to turn the object around.
Therefore, if you take a large piece of a substance, then its average force of interaction with a magnet will be very small.
Iron and metals similar to it have a special feature - the connection between neighboring atoms is such that they sense the magnetic field in a coordinated manner. If a few atoms are tuned to be attracted to a magnet, they will cause all neighboring atoms to do the same. As a result, in a piece of iron all the atoms “want to attract” or “want to repel” at once, and because of this, a very large force of interaction with the magnet is obtained.
A magnet is a body that has its own magnetic field. In a magnetic field, there is some effect on external objects that are nearby, the most obvious being the ability of a magnet to attract metal.
The magnet and its properties were known to both the ancient Greeks and the Chinese. They noticed a strange phenomenon: small pieces of iron were attracted to some natural stones.
This phenomenon was first called divine and used in rituals, but with the development of natural science it became obvious that the properties were of a completely earthly nature, which was first explained by the physicist from Copenhagen Hans Christian Oersted.
He discovered in 1820 a certain connection between the electric discharge of current and a magnet, which gave rise to the doctrine of electric current and magnetic attraction.
Natural science research
Natural science research
Oersted, conducting experiments with a magnetic needle and a conductor, noticed the following feature: a discharge of energy directed towards the needle instantly acted on it, and it began to deviate.
The arrow always deviated, no matter from which side he approached.
A physicist from France, Dominique François Arago, began repeated experiments with a magnet, using as a basis a glass tube rewound with a metal thread, and he installed an iron rod in the middle of this object.
With the help of electricity, the iron inside began to be sharply magnetized, because of this various keys began to stick, but as soon as the discharge was turned off, the keys immediately fell to the floor.
Based on what was happening, a physicist from France, Andre Ampere, developed an accurate description of everything that happened in this experiment.
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear. If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines). Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Magnetic effect
Magnetic effect
Today it is obvious that the matter is not in miracles, but in a more than unique characteristic of the internal structure of the electronic circuits that form magnets. An electron that constantly rotates around an atom forms the same magnetic field.
Microatoms have a magnetic effect and are in complete equilibrium, but magnets, with their attraction, influence some types of metals, such as iron, nickel, cobalt.
These metals are also called ferromagnets. In close proximity to a magnet, atoms immediately begin to rearrange and form magnetic poles.
Atomic magnetic fields exist in an ordered system; they are also called domains. In this characteristic system there are two poles opposite to each other - north and south.
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Date Category: Physics
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
- Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear.
- If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines).
- Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Source: https://Information-Technology.ru/sci-pop-articles/23-physics/231-pochemu-magnit-prityagivaet-zhelez
Difference between neodymium magnet and ordinary magnet
The main difference between neodymium magnet and ordinary magnet is that neodymium magnet contains neodymium, iron and boron as the key chemical elements, while ordinary magnet contains iron as the main chemical element.
A neodymium magnet is a type of magnet with strong magnetism made from rare earth elements such as neodymium. It is an alloy of several metals such as iron, boron, etc. Whereas, conventional magnets are ceramic magnets which contain ferrite as the main compound. It contains a high percentage of iron(III) oxide along with some other metals such as barium. These magnets are popular due to their low cost and fairly high magnetism strength.
- Overview and main differences
- What is a neodymium magnet
- What is a regular magnet
- What is the difference between a neodymium magnet and a regular magnet
- Conclusion
What is a neodymium magnet?
A neodymium magnet is a type of rare earth magnet that contains neodymium, iron and boron. This is a permanent magnet. It has an alloy of these metals in the form of a tetragonal crystal structure Nd2Fe14B. This magnet is the strongest commercial grade magnet currently available. Therefore, these magnets can replace many other types of magnets in modern products such as motors in cordless tools.
Neodymium is a ferromagnetic material; so we can magnetize it so that it becomes a magnet. However, the Curie temperature (the material at which a magnet loses magnetism) of this element is very low. Therefore, in its pure form it exhibits magnetism at very low temperatures. But if we make an alloy of neodymium with some transition metals such as iron, we can improve the magnetism of this material. This is a “neodymium magnet”.
Neodymium magnetic balls
There are several factors that determine the strength of this magnet. The main factor is the tetragonal crystal structure of this alloy.
In addition, the neodymium atom also has a significant magnetic dipole moment due to the presence of 4 unpaired electrons.
In addition to this, these magnets have exceptionally high residual coefficient (magnetic field strength), coercivity (material's resistance to demagnetization) and magnetic energy density. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively low.
What is a regular magnet?
Regular magnets are magnets that we use for common purposes. In most cases we use ceramic (or ferrite) magnets. These magnets contain ferrite as the main component. Ferrite is a ceramic material. It is mainly composed of iron(III) oxide. and there are also some other metals such as barium, manganese, nickel and zinc. These components are ferromagnetic and electrically non-conductive.
Ceramic magnets
In addition, these magnets have a relatively low residual magnetic induction (magnetic field strength) and coercive force (material resistance to demagnetization). But there are two types of ferrite magnets: hard ferrites and soft ferrites depending on the coercivity (high and low respectively). The magnetic energy density is also very low. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively high.
Source: https://raznisa.ru/raznica-mezhdu-neodimovym-magnitom-i-obychnym-magnitom/
How a magnet affects us: the whole truth about magnetic jewelry
Nowadays, treatment is mainly based on medications. Pharmacy shelves are filled with various tablets, capsules, syrups and drops.
In addition to their beneficial effect, they have many side effects on the body: they overload the liver and kidneys, and negatively affect the immune system. In addition, they are addictive, so when their therapeutic effect is needed most, there is no need to wait for it.
Of course, we are mainly talking about patients with chronic pathology, which requires constant monitoring and correction of the condition, and systematic use of medications.
In order to relieve the body of medications, but at the same time “keep the disease in check,” more and more doctors are trying to dilute the treatment with physiotherapy. There are many similar techniques, each with its own vectors of work. In this article we will take a closer look at magnetic therapy.
History of magnetic therapy
Magnetotherapy is a physiotherapeutic technique based on the effect of a magnetic field on the human body.
Since ancient times, people have been interested in magnetic fields. Their existence was first noticed about 2 thousand years ago. Over time, it found practical application in the form of a compass. According to historical documents, it was first noticed in China 1 thousand years before the new era that a long piece of magnetic iron attached to a plug floating in a liquid pointed north.
Since then, people began to find new uses for this important invention. Without it, it would have been impossible to create cars, ships, tape recorders, etc. In medicine, the magnet also played an undeniable role.
Doctors of ancient times (immediately after the discovery of the properties of a magnet) began to study its effect on the human body. Initially, data on its properties for humans were contradictory. Some considered the magnet a potent poison, while others considered it a panacea. The history of medicine knows many cases of the use of magnets as a remedy:
- Hippocrates used magnetic powder as a laxative.
- Cleopatra constantly wore a magnetic necklace, which was supposed to preserve her beauty and youth.
- Queen Elizabeth I suffered from arthritis. According to the documents, she was treated with magnets.
- Franz Antoine Mesmer cured many people using magnets. He successfully practiced in Vienna and Paris, where, as part of the team of the Royal Society of Medicine, he tried to use this technique to heal people with seizures and nervous diseases. They used magnets in the form of rings, bracelets, and amulets. After conducting many experiments, Mesmer came to the conclusion that our body is surrounded by a magnetic field, and direct influence on it can help cure many diseases.
- After the Civil War, there was a real shortage of qualified medical personnel in the United States. This led to the spread of folk remedies. Magnets were especially popular. They were used in the form of insoles, bandages, and rings. They have been successfully used as a pain reliever.
- At the beginning of the 19th century, more and more articles began to appear scientifically substantiating the use of magnetic therapy.
Nowadays, this type of physiotherapy has become especially widespread in the USA, China, and Japan. Many means, methods and types of magnetic therapy have been developed, which are successfully used in various branches of medicine.
Scientific rationale for magnetic therapy
How and why does it work? How can a small bracelet help you cure a huge list of diseases?
Thanks to physics, we know that everything in the world has its own magnetic fields. Man is no exception. Our magnetic field is formed due to the flow of blood through the vessels. It consists of metal ions, which, when circulating, form a static magnetic field. It is present where there are blood vessels in our body, that is, absolutely everywhere.
When we are exposed to a magnetic field, electric currents are generated in the body. Because of this, a number of changes occur:
- changes in the configuration of cell membranes and their structural units (lysosomes, mitochondria, etc.);
- changes in cell membrane permeability;
- changes in the course of chemical reactions in the body that occur with the participation of free radicals (almost all processes in which enzymes are involved);
- changes in the physicochemical properties of all body fluids;
- reorientation of large molecules (including proteins, fats, carbohydrates).
By influencing these basic processes in the body, you can regulate its condition. Currently, many studies have been conducted that confirm the effectiveness of magnetic therapy. They make it possible to become an alternative to heavy medication load.
Types of magnetic therapy
Thanks to technological progress, several types of magnets are available to us that can be used for therapeutic purposes. Magnetic therapy is differentiated based on the type of magnetic fields: variable and constant. There is also a distinction between general magnetic therapy (when the effect occurs on the entire body as a whole) and local (the effect is carried out locally: on a joint, a separate organ or area).
If we talk about technical equipment, there are now three main types of devices available:
- Stationary. It consists of a table, a magnet and a computer, which contains several basic treatment protocols. The patient lies down on the table, and the physiotherapist selects the necessary protocol. The device can also be equipped with additional components (a magnet for local, directional influence, a belt, a solenoid that allows you to create a circular magnetic field). Treatment usually takes place in courses. One session lasts from 15 to 40 minutes. No special preparation is required. The only recommendation is to drink a glass of water before the procedure to slightly enhance the effect of the device.
- Portable. It is a device that the patient can easily carry with him. The effect is carried out by applying the device to the affected area of the body or wearing it in this area. The most popular device is considered to be “Magofon-01”, which creates special vibroacoustic vibrations and a low-frequency magnetic field. This type of device has pronounced analgesic, anti-edematous and anti-inflammatory effects.
- Magnetic jewelry. Patients wishing to purchase magnetic jewelry have a wide range of choices: rings, bracelets, necklaces, watches, earrings, brooches, etc. They are often elegantly and tastefully made. Naturally, it is difficult to suspect a medicinal product in these accessories. They are usually made of copper, metal, or jewelry steel. Active magnets are placed on their inner surface. It is the latter that have a special field; accordingly, they are made with extreme care in order to help and not harm a person.
The impact of magnetic jewelry on the human body
Magnets change our state at the molecular level. This affects the organs and their performance, which allows doctors to recommend them as an additional treatment for a number of pathologies.
The main beneficial therapeutic effects of magnetic jewelry include:
- Improving microcirculation. Blood circulation under the influence of magnetic fields improves throughout the body, including blood circulation in the brain. This effect is realized due to an increase in the lumen of the smallest vessels in our body - capillaries. At the same time, the speed of blood flow in vessels of medium and large caliber is optimized.
- Reduced blood viscosity. This effect helps prevent the formation of blood clots.
- Improving the permeability of the vascular wall. It also optimizes blood flow while slowly clearing cholesterol deposits from the blood vessels.
- Normalization of lymphatic drainage. Magnetic fields have a beneficial effect on lymphatic vessels, expanding their lumen. This promotes better lymph outflow, reducing tissue swelling and accelerating the process of removing by-products of metabolic processes.
- Stimulation of tissue nutrition. This implies that tissues begin to receive more nutrients when using magnetic jewelry. Metabolism at the cellular level is enhanced, which improves recovery and regeneration processes in the body.
- Anti-inflammatory effect. Reducing swelling, improving blood circulation in organs and optimizing the synthesis of anti-inflammatory substances (prostaglandins) contributes to a faster resolution of inflammatory processes in the body.
- Regulation of the nervous system. This technique allows you to activate the processes of excitation or inhibition of the nervous system, depending on the type of magnetic therapy and the point of application.
- Decreased sensitivity of pain receptors. The impact on this type of receptor allows magnetic jewelry to realize an analgesic effect. In addition, there are studies that clearly demonstrate that magnetic fields can lead to the regeneration of nerve fibers and improve the conduction of impulses through them.
For what diseases are magnetic jewelry recommended?
Considering these effects of magnetic jewelry, it is advisable to use them for diseases such as:
Pathology of the cardiovascular system |
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Pathology of the nervous system |
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Diseases of the bronchopulmonary system and ENT organs |
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Diseases of the musculoskeletal system |
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Diseases of the gastrointestinal tract |
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Pathology of the urinary and reproductive system |
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Oral diseases |
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Pathologies of the visual analyzer |
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Skin diseases |
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Endocrine system |
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Source: https://fitexpert.biz/magnity/
Why does a magnet attract - all about magnetic fields
Why does a magnet attract?
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles.
Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other. The north pole of one magnet repels the north pole of the other.
Magnetic and electric current
The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
Magnetic field lines
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road.
For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
Related materials:
Gravitational interaction
Electron movement and magnetic field
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the electron around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
Why materials are magnetic and not magnetic
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction. That is, each domain is a small magnet.
Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if we manage to orient the domains in one direction so that the forces of the magnetic fields add up, then watch out! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Interesting fact: the mineral iron ore is a natural magnet. But still, most magnets are made artificially.
What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field. As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet.
Related materials:
How are magnets made?
You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large horseshoe magnet. Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Source: https://kipmu.ru/pochemu-magnit-prityagivaet-ili-vse-o-magnitnyx-polyax/
Neodymium magnet: what does it mean and what is it made of, how to use
Neodymium magnet is the most powerful and permanent magnet, which contains rare earth neodymium, boron and iron. What is the complete definition of a magnet and its main advantages, what is its strength and what is its principle of operation? More on this later.
What it is
A neodymium magnet is a magnetic element that is composed of neodymium rare earth boron and iron material. It has a crystal structure, tetragonal shape and formula Nd2Fe14B.
Neodymium magnet is the most common type
It was first created by General Motors in 1982. It is the strongest permanent magnetic element, the power of which is several times greater than usual. Equipped with a large magnetic induction of 12,400 gauss.
Note! This is a brittle alloy with the formula NdFeB, as well as a hard nickel-plated protective layer and the corresponding class. It is very popular and comes in various forms.
Full material definition
Advantages
The most common neodymium magnet is one that has an iron oxide alloy, which has good heat resistance, high magnetic permeability and low cost. Equipped with color coding, high coercivity, powerful magnetic field to hold objects suspended, compact size, light weight, affordable and wide range of applications. Has a long service life.
If an ordinary magnet works for 10 years and can be demagnetized, then a neodymium magnet does not lose its properties after 100 years. Another advantage is the shape. This product has a horseshoe shape. It gives the device a long service life. As for the cost, these are expensive products, but the cost is justified by excellent performance and impeccable reliability.
Durability of work as one of the advantages
Force
It is worth pointing out that the strength contained in neodymium magnets is another advantage. She is tall and it is impossible to find a competitor to her. This is a record type of indicator, the increase of which is impossible. Power is generated during manufacturing. Magnetization occurs after the alloy is formed. Thanks to existing technologies, the alloy is magnetized in such a way that the magnet has incredibly high power and this figure reaches a record.
Note! Power is a relative philistine concept. The force is stable, but it is measured using instruments. In this case, the readings depend on the thickness of the surface and cleanliness. The separation angle can have some influence.
Strength as one of the advantages
Life time
The service life of the equipment, if used properly, is 30 years. Due to careless handling, the device may be damaged. The point is the lack of flexibility, as well as brittleness and cracking under heavy load. Falls, impacts, or reduced traction will reduce the life of the equipment. For this reason, it is necessary to avoid falls using parts that come into contact during movements.
Another extremely important point is the irreversible loss of magnetic properties due to heating. Therefore, grinding with cutting or drilling reduces the chain force and may ignite the alloy. If storage and operation are organized correctly, then magnetization is maintained for 10 years.
Long service life
Design
When answering the question of what a neodymium magnet is made of, we can point out that it is a rare earth element that contains an atom with lanthanide or actinide. The classic composition may still contain an additive.
It is used to increase strength with endurance and resistance to high temperatures. Boron is used in small quantities, iron is a binding element. Thanks to this composition, greater adhesion is obtained.
When connecting several ferrite rings, you can separate them with your hands. As for neodymium magnets, this cannot be done.
Composition of magnetic material
How are neodymium magnets magnetized?
The magnetization of neodymium magnets occurs through the interaction of bromine ions, iron and neodymium in a powerful magnetic field. Thanks to such actions, an element is obtained that has a high coercive force and high adhesion power. It also has an extremely long service life in everyday life.
Magnetization of neodymium materials
Principle of operation
A neodymium magnet works very simply. If two magnetic elements are connected and the poles coincide in direction, the magnetic force of the two fields will be enhanced. The result is an overall strong magnetic field. With the reverse arrangement of the magnetized elements, the magnetic field will be suppressed.
Principle of operation
How to use
Neodymium magnetic element is the strongest, exceeding analogues that are based on rare earth metal. In addition, neodymium is capable of maintaining a magnetized structure for a significantly long time. Such equipment can be used in various fields. For example, it is used in the manufacture of over-ear headphones with wind generators, motor wheels and scooters.
Note! Magnets are actively used in industrial, household, and medical fields. They are also used to carry out search work with a metal detector. They can often be found in plumbing fixtures or souvenirs.
Specific examples include the use of magnets in the development of medical devices, magnetic treatment of water, the creation of oil and technological filters, and the formation of actuators with highly sensitive sensors. In addition, they are needed to produce clothes with covers and shoes, and to create advertising, information and navigation materials.
Scope of application of the material
Overall, neodymium is the most powerful permanent magnetic material that has high resistance to demagnetization, attractive power, and a metallic appearance. It has a long service life and consists of boron, iron and a metal of the lanthanide group.
Source: https://rusenergetics.ru/polezno-znat/neodimovykh-magnitakh
Permanent magnets, their description and principle of operation:
Along with pieces of amber electrified by friction, permanent magnets were for ancient people the first material evidence of electromagnetic phenomena (lightning at the dawn of history was definitely attributed to the sphere of manifestation of immaterial forces).
Explaining the nature of ferromagnetism has always occupied the inquisitive minds of scientists, however, even now the physical nature of the permanent magnetization of some substances, both natural and artificially created, has not yet been fully revealed, leaving a considerable field of activity for modern and future researchers.
Traditional materials for permanent magnets
They have been actively used in industry since 1940 with the advent of alnico alloy (AlNiCo). Previously, permanent magnets made of various types of steel were used only in compasses and magnetos. Alnico made it possible to replace electromagnets with them and use them in devices such as motors, generators and loudspeakers.
This penetration into our daily lives received a new impetus with the creation of ferrite magnets, and since then permanent magnets have become commonplace.
The revolution in magnetic materials began around 1970, with the creation of the samarium-cobalt family of hard magnetic materials with previously unheard-of magnetic energy densities.
Then a new generation of rare earth magnets was discovered, based on neodymium, iron and boron, with a much higher magnetic energy density than samarium cobalt (SmCo) and at an expectedly low cost.
These two families of rare earth magnets have such high energy densities that they can not only replace electromagnets, but be used in areas that are inaccessible to them. Examples include the tiny permanent magnet stepper motor in wristwatches and the sound transducers in Walkman-type headphones.
The gradual improvement in the magnetic properties of materials is shown in the diagram below.
Neodymium permanent magnets
They represent the latest and most significant development in this field over the past decades. Their discovery was first announced almost simultaneously at the end of 1983 by metal specialists from Sumitomo and General Motors. They are based on the intermetallic compound NdFeB: an alloy of neodymium, iron and boron. Of these, neodymium is a rare earth element extracted from the mineral monazite.
The enormous interest that these permanent magnets have generated arises because for the first time a new magnetic material has been produced that is not only stronger than the previous generation, but is more economical.
It consists mainly of iron, which is much cheaper than cobalt, and neodymium, which is one of the most common rare earth materials and has more reserves on Earth than lead.
The major rare earth minerals monazite and bastanesite contain five to ten times more neodymium than samarium.
Physical mechanism of permanent magnetization
To explain the functioning of a permanent magnet, we must look inside it down to the atomic scale. Each atom has a set of spins of its electrons, which together form its magnetic moment.
For our purposes, we can consider each atom as a small bar magnet. When a permanent magnet is demagnetized (either by heating it to a high temperature or by an external magnetic field), each atomic moment is oriented randomly (see Fig.
below) and no regularity is observed.
When it is magnetized in a strong magnetic field, all atomic moments are oriented in the direction of the field and, as it were, interlocked with each other (see figure below). This coupling allows the permanent magnet field to be maintained when the external field is removed, and also resists demagnetization when its direction is changed. A measure of the cohesive force of atomic moments is the magnitude of the coercive force of the magnet. More on this later.
In a more in-depth presentation of the magnetization mechanism, one does not operate with the concepts of atomic moments, but uses ideas about miniature (of the order of 0.001 cm) regions inside the magnet, which initially have permanent magnetization, but are randomly oriented in the absence of an external field, so that a strict reader, if desired, can attribute the above physical The mechanism is not related to the magnet as a whole. but to its separate domain.
Induction and magnetization
The atomic moments are summed up and form the magnetic moment of the entire permanent magnet, and its magnetization M shows the magnitude of this moment per unit volume. Magnetic induction B shows that a permanent magnet is the result of an external magnetic force (field strength) H applied during primary magnetization, as well as an internal magnetization M due to the orientation of atomic (or domain) moments. Its value in the general case is given by the formula:
B = µ0 (H + M),
where µ0 is a constant.
In a permanent ring and homogeneous magnet, the field strength H inside it (in the absence of an external field) is equal to zero, since, according to the law of total current, the integral of it along any circle inside such a ring core is equal to:
H∙2πR = iw=0, whence H=0.
Therefore, the magnetization in a ring magnet is:
M = B/µ0.
In an open magnet, for example, in the same ring magnet, but with an air gap of width lzaz in a core of length lser, in the absence of an external field and the same induction B inside the core and in the gap, according to the law of total current, we obtain:
Hser l ser + (1/ µ0)Blzaz = iw=0.
Since B = µ0(Hser + Mser), then, substituting its expression into the previous one, we get:
Hser(l ser + lzaz) + Mser lzaz=0,
or
Hser = ─ Mser lzaz(l ser + lzaz).
In the air gap:
Hzaz = B/µ0,
wherein B is determined by the given Mser and the found Hser.
Magnetization curve
Starting from the unmagnetized state, when H increases from zero, due to the orientation of all atomic moments in the direction of the external field, M and B quickly increase, changing along section “a” of the main magnetization curve (see figure below).
When all atomic moments are equalized, M comes to its saturation value, and a further increase in B occurs solely due to the applied field (section b of the main curve in the figure below).
When the external field decreases to zero, the induction B decreases not along the original path, but along section “c” due to the coupling of atomic moments, tending to maintain them in the same direction. The magnetization curve begins to describe the so-called hysteresis loop.
When H (external field) approaches zero, the induction approaches a residual value determined only by atomic moments:
Br = μ0 (0 + Mg).
After the direction of H changes, H and M act in opposite directions and B decreases (part of the curve “d” in the figure). The value of the field at which B decreases to zero is called the coercive force of the BHC magnet.
When the magnitude of the applied field is large enough to break the cohesion of the atomic moments, they are oriented in the new direction of the field, and the direction of M is reversed. The field value at which this occurs is called the internal coercive force of the permanent magnet MHC.
So, there are two different but related coercive forces associated with a permanent magnet.
The figure below shows the basic demagnetization curves of various materials for permanent magnets. It shows that NdFeB magnets have the highest residual induction Br and coercive force (both total and internal, i.e., determined without taking into account the strength H, only by the magnetization M).
Surface (ampere) currents
The magnetic fields of permanent magnets can be considered as the fields of some associated currents flowing along their surfaces. These currents are called Ampere currents. In the usual sense of the word, there are no currents inside permanent magnets.
However, comparing the magnetic fields of permanent magnets and the fields of currents in coils, the French physicist Ampere suggested that the magnetization of a substance can be explained by the flow of microscopic currents, forming microscopic closed circuits.
And indeed, the analogy between the field of a solenoid and a long cylindrical magnet is almost complete: there is a north and south pole of a permanent magnet and the same poles of the solenoid, and the patterns of force lines of their fields are also very similar (see figure below).
Are there currents inside a magnet?
Let's imagine that the entire volume of a bar permanent magnet (with an arbitrary cross-sectional shape) is filled with microscopic Ampere currents. A cross section of a magnet with such currents is shown in the figure below. Each of them has a magnetic moment. With the same orientation in the direction of the external field, they form a resulting magnetic moment that is different from zero.
It determines the existence of a magnetic field in the apparent absence of ordered movement of charges, in the absence of current through any cross section of the magnet. It is also easy to understand that inside it, the currents of adjacent (contacting) circuits are compensated. Only the currents on the surface of the body, which form the surface current of a permanent magnet, are uncompensated.
Its density turns out to be equal to the magnetization M.
How to get rid of moving contacts
The problem of creating a contactless synchronous machine is known. Its traditional design with electromagnetic excitation from the poles of a rotor with coils involves supplying current to them through movable contacts - slip rings with brushes.
The disadvantages of such a technical solution are well known: they are difficulties in maintenance, low reliability, and large losses in moving contacts, especially when it comes to powerful turbo and hydrogen generators, the excitation circuits of which consume considerable electrical power.
If you make such a generator using permanent magnets, then the contact problem immediately goes away. However, there is a problem of reliable fastening of magnets on a rotating rotor. This is where the experience gained in tractor manufacturing can come in handy. They have long been using an inductor generator with permanent magnets located in rotor slots filled with a low-melting alloy.
Permanent magnet motor
In recent decades, DC motors have become widespread. Such a unit consists of the electric motor itself and an electronic commutator for its armature winding, which performs the functions of a collector.
The electric motor is a synchronous motor with permanent magnets located on the rotor, as in Fig. above, with a stationary armature winding on the stator.
Electronic switch circuitry is an inverter of direct voltage (or current) of the supply network.
The main advantage of such a motor is its non-contact nature. Its specific element is a photo-, induction or Hall rotor position sensor that controls the operation of the inverter.
Source: https://syl.ru/article/203617/new_postoyannyie-magnityi-ih-opisanie-i-printsip-deystviya
What metals are not magnetic and why?
Any child knows that metals are attracted to magnets. After all, they have more than once hung magnets on the metal door of the refrigerator or letters with magnets on a special board. However, if you put a spoon against a magnet, there will be no attraction. But the spoon is also metal, so why does this happen? So, let's find out which metals are not magnetic.
Scientific point of view
To determine which metals are not magnetic, you need to find out how all metals in general can relate to magnets and a magnetic field. With respect to the applied magnetic field, all substances are divided into diamagnetic, paramagnetic and ferromagnetic.
Each atom consists of a positively charged nucleus and negatively charged electrons. They move continuously, which creates a magnetic field. The magnetic fields of electrons in one atom can enhance or cancel each other, depending on the direction of their movement. Moreover, the following can be compensated:
- Magnetic moments caused by the movement of electrons relative to the nucleus are orbital.
- Magnetic moments caused by the rotation of electrons around their axis are spin moments.
If all magnetic moments are equal to zero, the substance is classified as diamagnetic. If only spin moments are compensated - to paramagnets. If the fields are not compensated, use ferromagnets.
Paramagnets and ferromagnets
Let's consider the option when each atom of a substance has its own magnetic field. These fields are multidirectional and compensate each other. If you place a magnet next to such a substance, the fields will be oriented in one direction. The substance will have a magnetic field, a positive and a negative pole.
Then the substance will be attracted to the magnet and can itself become magnetized, that is, it will attract other metal objects. For example, you can magnetize steel clips at home. Each one will have a negative and a positive pole, and you can even hang a whole chain of paper clips on a magnet.
Such substances are called paramagnetic.
Ferromagnets are a small group of substances that are attracted to magnets and are easily magnetized even in a weak field.
Diamagnets
In diamagnetic materials, the magnetic fields inside each atom are compensated. In this case, when a substance is introduced into a magnetic field, the movement of electrons under the influence of the field will be added to the natural movement of electrons. This movement of electrons will cause an additional current, the magnetic field of which will be directed against the external field. Therefore, the diamagnetic material will be weakly repelled from the nearby magnet.
So, if we approach the question from a scientific point of view, which metals are not magnetic, the answer will be – diamagnetic.
Distribution of paramagnets and diamagnets in the periodic table of Mendeleev elements
The magnetic properties of simple substances change periodically with increasing atomic number of the element.
Substances that are not attracted to magnets (diamagnets) are located mainly in short periods - 1, 2, 3. Which metals are not magnetic? These are lithium and beryllium, and sodium, magnesium and aluminum are already classified as paramagnetic.
Substances that are attracted to magnets (paramagnets) are located mainly in the long periods of the Mendeleev periodic system - 4, 5, 6, 7.
However, the last 8 elements in each long period are also diamagnetic.
In addition, three elements are distinguished - carbon, oxygen and tin, the magnetic properties of which are different for different allotropic modifications.
In addition, there are 25 more chemical elements whose magnetic properties could not be established due to their radioactivity and rapid decay or the complexity of synthesis.
The magnetic properties of lanthanides and actinides (all of which are metals) change irregularly. Among them there are para- and diamagnetic materials.
There are special magnetically ordered substances - chromium, manganese, iron, cobalt, nickel, the properties of which change irregularly.
What metals are not magnetic: list
There are only 9 ferromagnets, that is, metals that are highly magnetic, in nature. These are iron, cobalt, nickel, their alloys and compounds, as well as six lanthanide metals: gadolinium, terbium, dysprosium, holmium, erbium and thulium.
Metals that are attracted only to very strong magnets (paramagnetic): aluminum, copper, platinum, uranium.
Since in everyday life there are no such large magnets that would attract a paramagnetic material, and also no lanthanide metals are found, we can safely say that all metals except iron, cobalt, nickel and their alloys will not be attracted to magnets.
So, what metals are not magnetic to a magnet:
- paramagnetic materials: aluminum, platinum, chromium, magnesium, tungsten;
- diamagnetic materials: copper, gold, silver, zinc, mercury, cadmium, zirconium.
In general, we can say that ferrous metals are attracted to a magnet, non-ferrous metals are not.
If we talk about alloys, then iron alloys are magnetic. These primarily include steel and cast iron. Precious coins can also be attracted to a magnet, since they are not made of pure non-ferrous metal, but of an alloy that may contain a small amount of ferromagnetic material. But jewelry made of pure non-ferrous metal will not be attracted to a magnet.
What metals do not rust and are not magnetic? These are ordinary food grade stainless steel, gold and silver items.
Source: https://FB.ru/article/435941/kakie-metallyi-ne-magnityatsya-i-pochemu
Why do magnets demagnetize - Metals and their processing
Employees of the site p-magnit.ru are sometimes asked about how to make a neodymium magnet with your own hands. Let's try to figure out how possible this is, and what the process of producing such products is all about.
So, the devices we sell consist of an alloy that is 70% iron and almost 30% boron. Only a fraction of a percent in its composition is made up of the rare earth metal neodymium, natural deposits of which are extremely rare in nature. Most of them are in China; they are found in only a few other countries, including Russia.
Before making neodymium magnets, manufacturers create molds for them from sand. Then the tray with the molds is doused with gas and subjected to heat treatment, due to which the sand hardens and retains the future outlines of the metal workpiece on its surface. Hot metal will later be placed in these forms, from which, in fact, the necessary products will be obtained.
Now let's directly look at how a neodymium magnet is made. Unlike ferromagnetic products, the metal here is not melted, but sintered from a powder mixture placed in an inert or vacuum environment.
Then the resulting magnetoplast is pressed while simultaneously exposing it to an electromagnetic field of a certain intensity. As you can see, even at the initial stage of production, it is noticeable that the question of how to make neodymium magnets at home sounds inappropriate.
The operations and equipment used are too complex. Creating such conditions at home is hardly possible.
After the workpieces are removed from the molds, they are subjected to mechanical processing - they are carefully polished, then they are fired to improve the coercive force of the products.
Finally, we come to the last steps, which will help to finally answer the question of how neodymium magnets are made. The sintered NdFeB alloy is again machine-finished using a special tool. During operation, a cooling lubricant is used to prevent overheating or ignition of the powder.
A protective coating is applied to the magnets. This is due, firstly, to the fact that sintered metals are quite fragile and need to be strengthened, and, secondly, the metal will be protected from corrosion processes and other environmental influences.
So manufacturers worry in advance about how to make a neodymium magnet stronger and more durable. The coating can be copper, nickel, zinc. In the last phase of the production process, magnetization is applied through a strong magnetic field.
Then they are sent to the warehouse, and from there to customers.
So, after we examined the production process in more or less detail, it became clear that we probably shouldn’t seriously ask the question “how to make a neodymium magnet at home.” After all, this requires not only certain knowledge, but many complex units.
How to completely demagnetize a neodymium magnet
Neodymium magnets are very popular in modern industry and in solving a number of everyday problems. If the buyer (for example) chose strong magnets for delivery in St. Petersburg, but violated the storage or transportation conditions, as a result of which they stuck together, it may be necessary to carry out a demagnetization procedure. The same action may be necessary in other cases when it is necessary for the product to lose its qualities.
The process can be carried out in various ways, including using factory equipment, and it is necessary to decide how to demagnetize a neodymium magnet taking into account your capabilities.
Methods for demagnetizing a magnet
Loss of the ability to attract metal objects can occur both naturally and during a number of actions. Subject to the rules of operation and storage, the qualities of neodymium elements are maintained for 100 years or more, and ferrite analogues continue to attract metal for 8-10 years. Degaussing neodymiums naturally is not practical if the procedure is to be performed on a new item.
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Product heating
This method is used both in industrial and domestic conditions: if the magnet is made of a standard alloy of neodymium with boron and iron, it will lose its properties when placed in water boiling at 80 degrees Celsius or in case of contact with a surface heated to the specified temperature.
If we are talking about a product with increased resistance to thermal shocks, it is unlikely that it will be possible to perform the procedure at home: the demagnetization temperature of neodymium magnets with such properties is 200 degrees Celsius.
To carry out the procedure in such cases, special industrial equipment is used.
Mechanical Actions
Neodymium can lose its qualities as a result of a strong directed impact, for example, an impact: this material has a powder structure that is destroyed when dropped from a height or when exposed to impact equipment. In addition, demagnetization can occur accidentally during the process of drilling or cutting a magnet: this is due to excessive mechanical pressure or an increase in the temperature of the product without forced cooling.
Treatment with external magnetic influence
Most often, if it is possible to use industrial equipment of increased power, another magnet is used, which allows the formation of a field with an induction force of about 4 Tesla. A neodymium magnet is demagnetized in a matter of seconds, so this method, despite its technological complexity, is characterized by the fastest possible result.
How to magnetize demagnetized neodymium
If the demagnetization of an element occurs accidentally, and it is necessary to return the product to its properties, it is impossible to do this at home. Restoring a neodymium magnet requires the use of a product that can create a very powerful field, and this requires the use of professional equipment used to create such items.
Usually, if you need to return the magnetization properties for a specific element, you contact a factory that specializes in the production of such products.
Is there anything I can do to make the magnet stronger?
If neodymium used for household purposes has become demagnetized, often a more appropriate solution would be to purchase a new element. The cost of magnetization work varies depending on the required properties and pricing policy of a particular production.
Application of neodymium magnet
These products are available in various shapes and sizes and are used for the following tasks:
- Creating a clamping effect, fixing metal elements to each other. Using neodymium magnets, you can attach an antenna, license plate, plate, other metal part, device or entire mechanism.
- Filtration of oil systems in cars and other equipment: neodymium magnets allow you to easily and quickly remove metal shavings.
- Creation of magnetic locks and fasteners used in industrial sectors and household purposes.
- Search work related to the search for metal objects (search for treasures, historical values, weapons, mine clearance work, etc.).
- Restoring other magnetic elements: using a neodymium element, you can create a magnetic field that will return the product to its ability to attract metal.
- Deleting information recorded on floppy disks, disks, flash drives and other electronic media for security purposes.
- Creation of devices for universal use (hangers, stirring devices, compasses, etc.).
- Construction of current generators that can be used as experimental models or devices suitable for domestic use.
- Making jewelry: Neodymium can come in different shapes and sizes, and beads made from this material are often given a chrome finish and can be painted in different colors.
- Treatment of water using magnetic influence, as a result of which the formation of scale is reduced, and the liquid itself acquires an improved taste and smell.
- Fuel conditioning, which allows you to reduce fuel consumption for cars and motorcycles.
- Sorting small metal items that need to be removed from a variety of non-metal items.
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Conclusion
Neodymium magnets are products that are widely used in commercial, industrial and household applications, they are characterized by high load capacity, excellent attractive properties and durability.
Before demagnetizing neodymium magnets, it is important to make sure that you have the necessary equipment: this requires either an industrial installation or a device for heating to at least 80 degrees.
Magnetizing products that have lost their quality is rarely advisable, but if necessary, you can order the procedure by contacting the manufacturer.
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Source: https://magnetline.ru/metally-i-splavy/pochemu-magnity-razmagnichivayutsya.html
Why putting a magnet on a meter is a bad idea
To reduce water and electricity bills, some people put powerful magnets on their meters. Under the influence of a magnetic field, even during the consumption of water and light, the device does not rotate.
But a magnet is not an innocent way to save money. If a person uses water and electricity, but does not pay for them, he steals, that is, he commits an administrative offense. In the laws, this is called theft and is punishable by a fine, temporary arrest or community service.
Inspectors will probably know about the magnet
It seems that if you install a magnet only occasionally and pay a little on the bills, then no one will know about the violation. But inspectors have several ways to detect theft:
- See the magnet. Usually they try not to let the inspectors in or quickly remove the magnet before opening the doors. But it may happen that the person who placed it will not be at home, the door will be opened by a child or a grandmother who has come to stay, or the residents will simply forget about the magnet. Then the inspector will take a photo of the violation and draw up a report, and then you will be issued a fine.
- Check the indicator. Modern water and light meters have special indicators, or magnetic field sensors. It is enough to bring a powerful magnet to the meter once - and the indicator will change color forever. And some of the most modern devices can even send a message to the dispatcher, so they will instantly know about the magnet.
- Measure the magnetic field. If a magnet has recently been placed on the meter, the magnetic field around it will be abnormally large. It can be measured using a special device - a Teslameter. And if the indicator can sometimes somehow be fooled, then the Teslameter cannot be fooled: it will clearly indicate that there was a magnet on the meter.
The Teslameter is expensive and is still rarely used, but gradually this method is becoming more and more popular. You can especially often find inspectors with teslameters in Moscow and St. Petersburg.
To record a violation and draw up a report, inspectors must come to the meter in person. To do this, management companies (MCs) arrange scheduled inspections every 1–2 years. Theoretically, you can adapt to them and use the magnet only immediately after the inspectors’ visit in order to save at least a little.
But if according to the general building meter the resource consumption is the same, but according to the sum of the apartment meters it is significantly less, this indicates theft on the part of the residents. In this case, the management company can arrange an unscheduled inspection and detect the magnet.
You will be punished for installing a magnet
Most often, on the basis of Government Resolution No. 354, they are required to pay the cost of resources tenfold. The cost is calculated according to average standards and multiplied by the time that has passed since the last inspection, but by a maximum of 3 months.
That is, if you install a magnet and it is discovered in six months, you will be forced to pay 10 times more than you would pay according to the standards for three months. Standards, by the way, are often too high.
Usually people spend less than the average per month, so the overpayment will be large.
This fine is not related to theft - it only relates to violation of the meter. If the Criminal Code decides to sue, the violator faces the following penalties:
- A fine of 10–15 thousand rubles for the unauthorized use of electrical, thermal energy, oil or gas, according to the Administrative Code.
- A fine of five times the value of the stolen property for petty theft up to 1 thousand rubles, according to the Administrative Code.
- A fine for petty theft is from 1 to 2.5 thousand rubles in the amount of five times the value of the stolen property, or arrest for 10–15 days, or up to 120 hours of community service.
Theoretically, when more than 2.5 thousand rubles are stolen, the crime is no longer considered administrative, but criminal. He faces a fine of up to 300 thousand rubles or imprisonment for 1–2 years. But in fact, such punishments are not imposed in the Russian Federation for magnets on meters.
You can save money without a magnet
To save money, you don't need to install a magnet. There are several legal ways to pay much less for electricity and water:
- Use LED lamps. They consume 8–10 times less electricity than conventional ones.
- Turn off the water when you are not using it. This is useful to do even in small things, such as while brushing your teeth or in the shower while you lather up.
- Always turn off the lights when leaving a room. You can install motion sensors so that the lights turn on and off automatically.
- Install aerators on taps. They break the stream into small droplets, which creates greater pressure but reduces water consumption.
- Use a washing machine and dishwasher. They use less water than hand washing or washing, and they also use cheaper cold water rather than hot water. Electricity consumption increases, but the final payment decreases.
- Fix all leaks in a timely manner.
- If the tank has one flush mode, place a bottle filled with water in it. This will slightly reduce the volume of the tank. There will still be enough water to rinse, but the consumption will decrease.
- Install a tank with two flush modes to waste less water.
- If cold water flows for a long time before hot water, you can drain it into a bucket. Then the water can be used for flushing, watering plants or other purposes.
Reasonable consumption of resources will help you save money even without magnets, so you don’t have to fear inspections and fines.
Source: https://Lifehacker.ru/magnit-na-schyotchik/
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles. Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other.
The north pole of one magnet repels the north pole of the other. The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road. For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the atom around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction.
That is, each domain is a small magnet. Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if you manage to orient the domains in one direction so that the forces of the magnetic fields combine, then beware! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Magnetic iron ore mineral is a natural magnet. But still, most magnets are made artificially. What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field.
As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet. You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large neodymium magnet.
Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Why doesn't a magnet attract everything?
In fact, the interaction of a magnet with substances has many more options than just “attracts” or “does not attract.” Iron, nickel, and some alloys are metals that, due to their specific structure, are very strongly attracted by a magnet.
The vast majority of other metals, as well as other substances, also interact with magnetic fields - they are attracted or repelled by magnets, but only thousands and millions of times weaker.
Therefore, in order to notice the attraction of such substances to a magnet, you need to use an extremely strong magnetic field, which you cannot get at home.
But since all substances are attracted to a magnet, the original question can be reformulated as follows: “Why then is iron so strongly attracted by a magnet that manifestations of this are easy to notice in everyday life?” The answer is: it is determined by the structure and bonding of iron atoms. Any substance is composed of atoms connected to each other by their outer electron shells.
It is the electrons of the outer shells that are sensitive to the magnetic field; they determine the magnetism of materials. In most substances, the electrons of neighboring atoms feel the magnetic field “at random” - some repel, others attract, and some generally try to turn the object around.
Therefore, if you take a large piece of a substance, then its average force of interaction with a magnet will be very small.
Iron and metals similar to it have a special feature - the connection between neighboring atoms is such that they sense the magnetic field in a coordinated manner. If a few atoms are tuned to be attracted to a magnet, they will cause all neighboring atoms to do the same. As a result, in a piece of iron all the atoms “want to attract” or “want to repel” at once, and because of this, a very large force of interaction with the magnet is obtained.
A magnet is a body that has its own magnetic field. In a magnetic field, there is some effect on external objects that are nearby, the most obvious being the ability of a magnet to attract metal.
The magnet and its properties were known to both the ancient Greeks and the Chinese. They noticed a strange phenomenon: small pieces of iron were attracted to some natural stones.
This phenomenon was first called divine and used in rituals, but with the development of natural science it became obvious that the properties were of a completely earthly nature, which was first explained by the physicist from Copenhagen Hans Christian Oersted.
He discovered in 1820 a certain connection between the electric discharge of current and a magnet, which gave rise to the doctrine of electric current and magnetic attraction.
Natural science research
Oersted, conducting experiments with a magnetic needle and a conductor, noticed the following feature: a discharge of energy directed towards the needle instantly acted on it, and it began to deviate.
The arrow always deviated, no matter from which side he approached.
A physicist from France, Dominique François Arago, began repeated experiments with a magnet, using as a basis a glass tube rewound with a metal thread, and he installed an iron rod in the middle of this object.
With the help of electricity, the iron inside began to be sharply magnetized, because of this various keys began to stick, but as soon as the discharge was turned off, the keys immediately fell to the floor.
Based on what was happening, a physicist from France, Andre Ampere, developed an accurate description of everything that happened in this experiment.
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear. If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines). Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Magnetic effect
Today it is obvious that the matter is not in miracles, but in a more than unique characteristic of the internal structure of the electronic circuits that form magnets. An electron that constantly rotates around an atom forms the same magnetic field.
Microatoms have a magnetic effect and are in complete equilibrium, but magnets, with their attraction, influence some types of metals, such as iron, nickel, cobalt.
These metals are also called ferromagnets. In close proximity to a magnet, atoms immediately begin to rearrange and form magnetic poles.
Atomic magnetic fields exist in an ordered system; they are also called domains. In this characteristic system there are two poles opposite to each other - north and south.
IT News
Date Category: Physics
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
- Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear.
- If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines).
- Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Source: https://Information-Technology.ru/sci-pop-articles/23-physics/231-pochemu-magnit-prityagivaet-zhelez
Difference between neodymium magnet and ordinary magnet
The main difference between neodymium magnet and ordinary magnet is that neodymium magnet contains neodymium, iron and boron as the key chemical elements, while ordinary magnet contains iron as the main chemical element.
A neodymium magnet is a type of magnet with strong magnetism made from rare earth elements such as neodymium. It is an alloy of several metals such as iron, boron, etc. Whereas, conventional magnets are ceramic magnets which contain ferrite as the main compound. It contains a high percentage of iron(III) oxide along with some other metals such as barium. These magnets are popular due to their low cost and fairly high magnetism strength.
- Overview and main differences
- What is a neodymium magnet
- What is a regular magnet
- What is the difference between a neodymium magnet and a regular magnet
- Conclusion
What is a neodymium magnet?
A neodymium magnet is a type of rare earth magnet that contains neodymium, iron and boron. This is a permanent magnet. It has an alloy of these metals in the form of a tetragonal crystal structure Nd2Fe14B. This magnet is the strongest commercial grade magnet currently available. Therefore, these magnets can replace many other types of magnets in modern products such as motors in cordless tools.
Neodymium is a ferromagnetic material; so we can magnetize it so that it becomes a magnet. However, the Curie temperature (the material at which a magnet loses magnetism) of this element is very low. Therefore, in its pure form it exhibits magnetism at very low temperatures. But if we make an alloy of neodymium with some transition metals such as iron, we can improve the magnetism of this material. This is a “neodymium magnet”.
Neodymium magnetic balls
There are several factors that determine the strength of this magnet. The main factor is the tetragonal crystal structure of this alloy.
In addition, the neodymium atom also has a significant magnetic dipole moment due to the presence of 4 unpaired electrons.
In addition to this, these magnets have exceptionally high residual coefficient (magnetic field strength), coercivity (material's resistance to demagnetization) and magnetic energy density. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively low.
What is a regular magnet?
Regular magnets are magnets that we use for common purposes. In most cases we use ceramic (or ferrite) magnets. These magnets contain ferrite as the main component. Ferrite is a ceramic material. It is mainly composed of iron(III) oxide. and there are also some other metals such as barium, manganese, nickel and zinc. These components are ferromagnetic and electrically non-conductive.
Ceramic magnets
In addition, these magnets have a relatively low residual magnetic induction (magnetic field strength) and coercive force (material resistance to demagnetization). But there are two types of ferrite magnets: hard ferrites and soft ferrites depending on the coercivity (high and low respectively). The magnetic energy density is also very low. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively high.
Source: https://raznisa.ru/raznica-mezhdu-neodimovym-magnitom-i-obychnym-magnitom/
How a magnet affects us: the whole truth about magnetic jewelry
Nowadays, treatment is mainly based on medications. Pharmacy shelves are filled with various tablets, capsules, syrups and drops.
In addition to their beneficial effect, they have many side effects on the body: they overload the liver and kidneys, and negatively affect the immune system. In addition, they are addictive, so when their therapeutic effect is needed most, there is no need to wait for it.
Of course, we are mainly talking about patients with chronic pathology, which requires constant monitoring and correction of the condition, and systematic use of medications.
In order to relieve the body of medications, but at the same time “keep the disease in check,” more and more doctors are trying to dilute the treatment with physiotherapy. There are many similar techniques, each with its own vectors of work. In this article we will take a closer look at magnetic therapy.
History of magnetic therapy
Magnetotherapy is a physiotherapeutic technique based on the effect of a magnetic field on the human body.
Since ancient times, people have been interested in magnetic fields. Their existence was first noticed about 2 thousand years ago. Over time, it found practical application in the form of a compass. According to historical documents, it was first noticed in China 1 thousand years before the new era that a long piece of magnetic iron attached to a plug floating in a liquid pointed north.
Since then, people began to find new uses for this important invention. Without it, it would have been impossible to create cars, ships, tape recorders, etc. In medicine, the magnet also played an undeniable role.
Doctors of ancient times (immediately after the discovery of the properties of a magnet) began to study its effect on the human body. Initially, data on its properties for humans were contradictory. Some considered the magnet a potent poison, while others considered it a panacea. The history of medicine knows many cases of the use of magnets as a remedy:
- Hippocrates used magnetic powder as a laxative.
- Cleopatra constantly wore a magnetic necklace, which was supposed to preserve her beauty and youth.
- Queen Elizabeth I suffered from arthritis. According to the documents, she was treated with magnets.
- Franz Antoine Mesmer cured many people using magnets. He successfully practiced in Vienna and Paris, where, as part of the team of the Royal Society of Medicine, he tried to use this technique to heal people with seizures and nervous diseases. They used magnets in the form of rings, bracelets, and amulets. After conducting many experiments, Mesmer came to the conclusion that our body is surrounded by a magnetic field, and direct influence on it can help cure many diseases.
- After the Civil War, there was a real shortage of qualified medical personnel in the United States. This led to the spread of folk remedies. Magnets were especially popular. They were used in the form of insoles, bandages, and rings. They have been successfully used as a pain reliever.
- At the beginning of the 19th century, more and more articles began to appear scientifically substantiating the use of magnetic therapy.
Nowadays, this type of physiotherapy has become especially widespread in the USA, China, and Japan. Many means, methods and types of magnetic therapy have been developed, which are successfully used in various branches of medicine.
Scientific rationale for magnetic therapy
How and why does it work? How can a small bracelet help you cure a huge list of diseases?
Thanks to physics, we know that everything in the world has its own magnetic fields. Man is no exception. Our magnetic field is formed due to the flow of blood through the vessels. It consists of metal ions, which, when circulating, form a static magnetic field. It is present where there are blood vessels in our body, that is, absolutely everywhere.
When we are exposed to a magnetic field, electric currents are generated in the body. Because of this, a number of changes occur:
- changes in the configuration of cell membranes and their structural units (lysosomes, mitochondria, etc.);
- changes in cell membrane permeability;
- changes in the course of chemical reactions in the body that occur with the participation of free radicals (almost all processes in which enzymes are involved);
- changes in the physicochemical properties of all body fluids;
- reorientation of large molecules (including proteins, fats, carbohydrates).
By influencing these basic processes in the body, you can regulate its condition. Currently, many studies have been conducted that confirm the effectiveness of magnetic therapy. They make it possible to become an alternative to heavy medication load.
Types of magnetic therapy
Thanks to technological progress, several types of magnets are available to us that can be used for therapeutic purposes. Magnetic therapy is differentiated based on the type of magnetic fields: variable and constant. There is also a distinction between general magnetic therapy (when the effect occurs on the entire body as a whole) and local (the effect is carried out locally: on a joint, a separate organ or area).
If we talk about technical equipment, there are now three main types of devices available:
- Stationary. It consists of a table, a magnet and a computer, which contains several basic treatment protocols. The patient lies down on the table, and the physiotherapist selects the necessary protocol. The device can also be equipped with additional components (a magnet for local, directional influence, a belt, a solenoid that allows you to create a circular magnetic field). Treatment usually takes place in courses. One session lasts from 15 to 40 minutes. No special preparation is required. The only recommendation is to drink a glass of water before the procedure to slightly enhance the effect of the device.
- Portable. It is a device that the patient can easily carry with him. The effect is carried out by applying the device to the affected area of the body or wearing it in this area. The most popular device is considered to be “Magofon-01”, which creates special vibroacoustic vibrations and a low-frequency magnetic field. This type of device has pronounced analgesic, anti-edematous and anti-inflammatory effects.
- Magnetic jewelry. Patients wishing to purchase magnetic jewelry have a wide range of choices: rings, bracelets, necklaces, watches, earrings, brooches, etc. They are often elegantly and tastefully made. Naturally, it is difficult to suspect a medicinal product in these accessories. They are usually made of copper, metal, or jewelry steel. Active magnets are placed on their inner surface. It is the latter that have a special field; accordingly, they are made with extreme care in order to help and not harm a person.
The impact of magnetic jewelry on the human body
Magnets change our state at the molecular level. This affects the organs and their performance, which allows doctors to recommend them as an additional treatment for a number of pathologies.
The main beneficial therapeutic effects of magnetic jewelry include:
- Improving microcirculation. Blood circulation under the influence of magnetic fields improves throughout the body, including blood circulation in the brain. This effect is realized due to an increase in the lumen of the smallest vessels in our body - capillaries. At the same time, the speed of blood flow in vessels of medium and large caliber is optimized.
- Reduced blood viscosity. This effect helps prevent the formation of blood clots.
- Improving the permeability of the vascular wall. It also optimizes blood flow while slowly clearing cholesterol deposits from the blood vessels.
- Normalization of lymphatic drainage. Magnetic fields have a beneficial effect on lymphatic vessels, expanding their lumen. This promotes better lymph outflow, reducing tissue swelling and accelerating the process of removing by-products of metabolic processes.
- Stimulation of tissue nutrition. This implies that tissues begin to receive more nutrients when using magnetic jewelry. Metabolism at the cellular level is enhanced, which improves recovery and regeneration processes in the body.
- Anti-inflammatory effect. Reducing swelling, improving blood circulation in organs and optimizing the synthesis of anti-inflammatory substances (prostaglandins) contributes to a faster resolution of inflammatory processes in the body.
- Regulation of the nervous system. This technique allows you to activate the processes of excitation or inhibition of the nervous system, depending on the type of magnetic therapy and the point of application.
- Decreased sensitivity of pain receptors. The impact on this type of receptor allows magnetic jewelry to realize an analgesic effect. In addition, there are studies that clearly demonstrate that magnetic fields can lead to the regeneration of nerve fibers and improve the conduction of impulses through them.
For what diseases are magnetic jewelry recommended?
Considering these effects of magnetic jewelry, it is advisable to use them for diseases such as:
Pathology of the cardiovascular system |
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Pathology of the nervous system |
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Diseases of the bronchopulmonary system and ENT organs |
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Diseases of the musculoskeletal system |
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Diseases of the gastrointestinal tract |
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Pathology of the urinary and reproductive system |
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Oral diseases |
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Pathologies of the visual analyzer |
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Skin diseases |
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Endocrine system |
|
Source: https://fitexpert.biz/magnity/
Why does a magnet attract - all about magnetic fields
Why does a magnet attract?
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles.
Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other. The north pole of one magnet repels the north pole of the other.
Magnetic and electric current
The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
Magnetic field lines
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road.
For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
Related materials:
Gravitational interaction
Electron movement and magnetic field
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the electron around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
Why materials are magnetic and not magnetic
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction. That is, each domain is a small magnet.
Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if we manage to orient the domains in one direction so that the forces of the magnetic fields add up, then watch out! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Interesting fact: the mineral iron ore is a natural magnet. But still, most magnets are made artificially.
What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field. As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet.
Related materials:
How are magnets made?
You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large horseshoe magnet. Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Source: https://kipmu.ru/pochemu-magnit-prityagivaet-ili-vse-o-magnitnyx-polyax/
Neodymium magnet: what does it mean and what is it made of, how to use
Neodymium magnet is the most powerful and permanent magnet, which contains rare earth neodymium, boron and iron. What is the complete definition of a magnet and its main advantages, what is its strength and what is its principle of operation? More on this later.
What it is
A neodymium magnet is a magnetic element that is composed of neodymium rare earth boron and iron material. It has a crystal structure, tetragonal shape and formula Nd2Fe14B.
Neodymium magnet is the most common type
It was first created by General Motors in 1982. It is the strongest permanent magnetic element, the power of which is several times greater than usual. Equipped with a large magnetic induction of 12,400 gauss.
Note! This is a brittle alloy with the formula NdFeB, as well as a hard nickel-plated protective layer and the corresponding class. It is very popular and comes in various forms.
Full material definition
Advantages
The most common neodymium magnet is one that has an iron oxide alloy, which has good heat resistance, high magnetic permeability and low cost. Equipped with color coding, high coercivity, powerful magnetic field to hold objects suspended, compact size, light weight, affordable and wide range of applications. Has a long service life.
If an ordinary magnet works for 10 years and can be demagnetized, then a neodymium magnet does not lose its properties after 100 years. Another advantage is the shape. This product has a horseshoe shape. It gives the device a long service life. As for the cost, these are expensive products, but the cost is justified by excellent performance and impeccable reliability.
Durability of work as one of the advantages
Force
It is worth pointing out that the strength contained in neodymium magnets is another advantage. She is tall and it is impossible to find a competitor to her. This is a record type of indicator, the increase of which is impossible. Power is generated during manufacturing. Magnetization occurs after the alloy is formed. Thanks to existing technologies, the alloy is magnetized in such a way that the magnet has incredibly high power and this figure reaches a record.
Note! Power is a relative philistine concept. The force is stable, but it is measured using instruments. In this case, the readings depend on the thickness of the surface and cleanliness. The separation angle can have some influence.
Strength as one of the advantages
Life time
The service life of the equipment, if used properly, is 30 years. Due to careless handling, the device may be damaged. The point is the lack of flexibility, as well as brittleness and cracking under heavy load. Falls, impacts, or reduced traction will reduce the life of the equipment. For this reason, it is necessary to avoid falls using parts that come into contact during movements.
Another extremely important point is the irreversible loss of magnetic properties due to heating. Therefore, grinding with cutting or drilling reduces the chain force and may ignite the alloy. If storage and operation are organized correctly, then magnetization is maintained for 10 years.
Long service life
Design
When answering the question of what a neodymium magnet is made of, we can point out that it is a rare earth element that contains an atom with lanthanide or actinide. The classic composition may still contain an additive.
It is used to increase strength with endurance and resistance to high temperatures. Boron is used in small quantities, iron is a binding element. Thanks to this composition, greater adhesion is obtained.
When connecting several ferrite rings, you can separate them with your hands. As for neodymium magnets, this cannot be done.
Composition of magnetic material
How are neodymium magnets magnetized?
The magnetization of neodymium magnets occurs through the interaction of bromine ions, iron and neodymium in a powerful magnetic field. Thanks to such actions, an element is obtained that has a high coercive force and high adhesion power. It also has an extremely long service life in everyday life.
Magnetization of neodymium materials
Principle of operation
A neodymium magnet works very simply. If two magnetic elements are connected and the poles coincide in direction, the magnetic force of the two fields will be enhanced. The result is an overall strong magnetic field. With the reverse arrangement of the magnetized elements, the magnetic field will be suppressed.
Principle of operation
How to use
Neodymium magnetic element is the strongest, exceeding analogues that are based on rare earth metal. In addition, neodymium is capable of maintaining a magnetized structure for a significantly long time. Such equipment can be used in various fields. For example, it is used in the manufacture of over-ear headphones with wind generators, motor wheels and scooters.
Note! Magnets are actively used in industrial, household, and medical fields. They are also used to carry out search work with a metal detector. They can often be found in plumbing fixtures or souvenirs.
Specific examples include the use of magnets in the development of medical devices, magnetic treatment of water, the creation of oil and technological filters, and the formation of actuators with highly sensitive sensors. In addition, they are needed to produce clothes with covers and shoes, and to create advertising, information and navigation materials.
Scope of application of the material
Overall, neodymium is the most powerful permanent magnetic material that has high resistance to demagnetization, attractive power, and a metallic appearance. It has a long service life and consists of boron, iron and a metal of the lanthanide group.
Source: https://rusenergetics.ru/polezno-znat/neodimovykh-magnitakh
Permanent magnets, their description and principle of operation:
Along with pieces of amber electrified by friction, permanent magnets were for ancient people the first material evidence of electromagnetic phenomena (lightning at the dawn of history was definitely attributed to the sphere of manifestation of immaterial forces).
Explaining the nature of ferromagnetism has always occupied the inquisitive minds of scientists, however, even now the physical nature of the permanent magnetization of some substances, both natural and artificially created, has not yet been fully revealed, leaving a considerable field of activity for modern and future researchers.
Traditional materials for permanent magnets
They have been actively used in industry since 1940 with the advent of alnico alloy (AlNiCo). Previously, permanent magnets made of various types of steel were used only in compasses and magnetos. Alnico made it possible to replace electromagnets with them and use them in devices such as motors, generators and loudspeakers.
This penetration into our daily lives received a new impetus with the creation of ferrite magnets, and since then permanent magnets have become commonplace.
The revolution in magnetic materials began around 1970, with the creation of the samarium-cobalt family of hard magnetic materials with previously unheard-of magnetic energy densities.
Then a new generation of rare earth magnets was discovered, based on neodymium, iron and boron, with a much higher magnetic energy density than samarium cobalt (SmCo) and at an expectedly low cost.
These two families of rare earth magnets have such high energy densities that they can not only replace electromagnets, but be used in areas that are inaccessible to them. Examples include the tiny permanent magnet stepper motor in wristwatches and the sound transducers in Walkman-type headphones.
The gradual improvement in the magnetic properties of materials is shown in the diagram below.
Neodymium permanent magnets
They represent the latest and most significant development in this field over the past decades. Their discovery was first announced almost simultaneously at the end of 1983 by metal specialists from Sumitomo and General Motors. They are based on the intermetallic compound NdFeB: an alloy of neodymium, iron and boron. Of these, neodymium is a rare earth element extracted from the mineral monazite.
The enormous interest that these permanent magnets have generated arises because for the first time a new magnetic material has been produced that is not only stronger than the previous generation, but is more economical.
It consists mainly of iron, which is much cheaper than cobalt, and neodymium, which is one of the most common rare earth materials and has more reserves on Earth than lead.
The major rare earth minerals monazite and bastanesite contain five to ten times more neodymium than samarium.
Physical mechanism of permanent magnetization
To explain the functioning of a permanent magnet, we must look inside it down to the atomic scale. Each atom has a set of spins of its electrons, which together form its magnetic moment.
For our purposes, we can consider each atom as a small bar magnet. When a permanent magnet is demagnetized (either by heating it to a high temperature or by an external magnetic field), each atomic moment is oriented randomly (see Fig.
below) and no regularity is observed.
When it is magnetized in a strong magnetic field, all atomic moments are oriented in the direction of the field and, as it were, interlocked with each other (see figure below). This coupling allows the permanent magnet field to be maintained when the external field is removed, and also resists demagnetization when its direction is changed. A measure of the cohesive force of atomic moments is the magnitude of the coercive force of the magnet. More on this later.
In a more in-depth presentation of the magnetization mechanism, one does not operate with the concepts of atomic moments, but uses ideas about miniature (of the order of 0.001 cm) regions inside the magnet, which initially have permanent magnetization, but are randomly oriented in the absence of an external field, so that a strict reader, if desired, can attribute the above physical The mechanism is not related to the magnet as a whole. but to its separate domain.
Induction and magnetization
The atomic moments are summed up and form the magnetic moment of the entire permanent magnet, and its magnetization M shows the magnitude of this moment per unit volume. Magnetic induction B shows that a permanent magnet is the result of an external magnetic force (field strength) H applied during primary magnetization, as well as an internal magnetization M due to the orientation of atomic (or domain) moments. Its value in the general case is given by the formula:
B = µ0 (H + M),
where µ0 is a constant.
In a permanent ring and homogeneous magnet, the field strength H inside it (in the absence of an external field) is equal to zero, since, according to the law of total current, the integral of it along any circle inside such a ring core is equal to:
H∙2πR = iw=0, whence H=0.
Therefore, the magnetization in a ring magnet is:
M = B/µ0.
In an open magnet, for example, in the same ring magnet, but with an air gap of width lzaz in a core of length lser, in the absence of an external field and the same induction B inside the core and in the gap, according to the law of total current, we obtain:
Hser l ser + (1/ µ0)Blzaz = iw=0.
Since B = µ0(Hser + Mser), then, substituting its expression into the previous one, we get:
Hser(l ser + lzaz) + Mser lzaz=0,
or
Hser = ─ Mser lzaz(l ser + lzaz).
In the air gap:
Hzaz = B/µ0,
wherein B is determined by the given Mser and the found Hser.
Magnetization curve
Starting from the unmagnetized state, when H increases from zero, due to the orientation of all atomic moments in the direction of the external field, M and B quickly increase, changing along section “a” of the main magnetization curve (see figure below).
When all atomic moments are equalized, M comes to its saturation value, and a further increase in B occurs solely due to the applied field (section b of the main curve in the figure below).
When the external field decreases to zero, the induction B decreases not along the original path, but along section “c” due to the coupling of atomic moments, tending to maintain them in the same direction. The magnetization curve begins to describe the so-called hysteresis loop.
When H (external field) approaches zero, the induction approaches a residual value determined only by atomic moments:
Br = μ0 (0 + Mg).
After the direction of H changes, H and M act in opposite directions and B decreases (part of the curve “d” in the figure). The value of the field at which B decreases to zero is called the coercive force of the BHC magnet.
When the magnitude of the applied field is large enough to break the cohesion of the atomic moments, they are oriented in the new direction of the field, and the direction of M is reversed. The field value at which this occurs is called the internal coercive force of the permanent magnet MHC.
So, there are two different but related coercive forces associated with a permanent magnet.
The figure below shows the basic demagnetization curves of various materials for permanent magnets. It shows that NdFeB magnets have the highest residual induction Br and coercive force (both total and internal, i.e., determined without taking into account the strength H, only by the magnetization M).
Surface (ampere) currents
The magnetic fields of permanent magnets can be considered as the fields of some associated currents flowing along their surfaces. These currents are called Ampere currents. In the usual sense of the word, there are no currents inside permanent magnets.
However, comparing the magnetic fields of permanent magnets and the fields of currents in coils, the French physicist Ampere suggested that the magnetization of a substance can be explained by the flow of microscopic currents, forming microscopic closed circuits.
And indeed, the analogy between the field of a solenoid and a long cylindrical magnet is almost complete: there is a north and south pole of a permanent magnet and the same poles of the solenoid, and the patterns of force lines of their fields are also very similar (see figure below).
Are there currents inside a magnet?
Let's imagine that the entire volume of a bar permanent magnet (with an arbitrary cross-sectional shape) is filled with microscopic Ampere currents. A cross section of a magnet with such currents is shown in the figure below. Each of them has a magnetic moment. With the same orientation in the direction of the external field, they form a resulting magnetic moment that is different from zero.
It determines the existence of a magnetic field in the apparent absence of ordered movement of charges, in the absence of current through any cross section of the magnet. It is also easy to understand that inside it, the currents of adjacent (contacting) circuits are compensated. Only the currents on the surface of the body, which form the surface current of a permanent magnet, are uncompensated.
Its density turns out to be equal to the magnetization M.
How to get rid of moving contacts
The problem of creating a contactless synchronous machine is known. Its traditional design with electromagnetic excitation from the poles of a rotor with coils involves supplying current to them through movable contacts - slip rings with brushes.
The disadvantages of such a technical solution are well known: they are difficulties in maintenance, low reliability, and large losses in moving contacts, especially when it comes to powerful turbo and hydrogen generators, the excitation circuits of which consume considerable electrical power.
If you make such a generator using permanent magnets, then the contact problem immediately goes away. However, there is a problem of reliable fastening of magnets on a rotating rotor. This is where the experience gained in tractor manufacturing can come in handy. They have long been using an inductor generator with permanent magnets located in rotor slots filled with a low-melting alloy.
Permanent magnet motor
In recent decades, DC motors have become widespread. Such a unit consists of the electric motor itself and an electronic commutator for its armature winding, which performs the functions of a collector.
The electric motor is a synchronous motor with permanent magnets located on the rotor, as in Fig. above, with a stationary armature winding on the stator.
Electronic switch circuitry is an inverter of direct voltage (or current) of the supply network.
The main advantage of such a motor is its non-contact nature. Its specific element is a photo-, induction or Hall rotor position sensor that controls the operation of the inverter.
Source: https://syl.ru/article/203617/new_postoyannyie-magnityi-ih-opisanie-i-printsip-deystviya
What metals are not magnetic and why?
Any child knows that metals are attracted to magnets. After all, they have more than once hung magnets on the metal door of the refrigerator or letters with magnets on a special board. However, if you put a spoon against a magnet, there will be no attraction. But the spoon is also metal, so why does this happen? So, let's find out which metals are not magnetic.
Scientific point of view
To determine which metals are not magnetic, you need to find out how all metals in general can relate to magnets and a magnetic field. With respect to the applied magnetic field, all substances are divided into diamagnetic, paramagnetic and ferromagnetic.
Each atom consists of a positively charged nucleus and negatively charged electrons. They move continuously, which creates a magnetic field. The magnetic fields of electrons in one atom can enhance or cancel each other, depending on the direction of their movement. Moreover, the following can be compensated:
- Magnetic moments caused by the movement of electrons relative to the nucleus are orbital.
- Magnetic moments caused by the rotation of electrons around their axis are spin moments.
If all magnetic moments are equal to zero, the substance is classified as diamagnetic. If only spin moments are compensated - to paramagnets. If the fields are not compensated, use ferromagnets.
Paramagnets and ferromagnets
Let's consider the option when each atom of a substance has its own magnetic field. These fields are multidirectional and compensate each other. If you place a magnet next to such a substance, the fields will be oriented in one direction. The substance will have a magnetic field, a positive and a negative pole.
Then the substance will be attracted to the magnet and can itself become magnetized, that is, it will attract other metal objects. For example, you can magnetize steel clips at home. Each one will have a negative and a positive pole, and you can even hang a whole chain of paper clips on a magnet.
Such substances are called paramagnetic.
Ferromagnets are a small group of substances that are attracted to magnets and are easily magnetized even in a weak field.
Diamagnets
In diamagnetic materials, the magnetic fields inside each atom are compensated. In this case, when a substance is introduced into a magnetic field, the movement of electrons under the influence of the field will be added to the natural movement of electrons. This movement of electrons will cause an additional current, the magnetic field of which will be directed against the external field. Therefore, the diamagnetic material will be weakly repelled from the nearby magnet.
So, if we approach the question from a scientific point of view, which metals are not magnetic, the answer will be – diamagnetic.
Distribution of paramagnets and diamagnets in the periodic table of Mendeleev elements
The magnetic properties of simple substances change periodically with increasing atomic number of the element.
Substances that are not attracted to magnets (diamagnets) are located mainly in short periods - 1, 2, 3. Which metals are not magnetic? These are lithium and beryllium, and sodium, magnesium and aluminum are already classified as paramagnetic.
Substances that are attracted to magnets (paramagnets) are located mainly in the long periods of the Mendeleev periodic system - 4, 5, 6, 7.
However, the last 8 elements in each long period are also diamagnetic.
In addition, three elements are distinguished - carbon, oxygen and tin, the magnetic properties of which are different for different allotropic modifications.
In addition, there are 25 more chemical elements whose magnetic properties could not be established due to their radioactivity and rapid decay or the complexity of synthesis.
The magnetic properties of lanthanides and actinides (all of which are metals) change irregularly. Among them there are para- and diamagnetic materials.
There are special magnetically ordered substances - chromium, manganese, iron, cobalt, nickel, the properties of which change irregularly.
What metals are not magnetic: list
There are only 9 ferromagnets, that is, metals that are highly magnetic, in nature. These are iron, cobalt, nickel, their alloys and compounds, as well as six lanthanide metals: gadolinium, terbium, dysprosium, holmium, erbium and thulium.
Metals that are attracted only to very strong magnets (paramagnetic): aluminum, copper, platinum, uranium.
Since in everyday life there are no such large magnets that would attract a paramagnetic material, and also no lanthanide metals are found, we can safely say that all metals except iron, cobalt, nickel and their alloys will not be attracted to magnets.
So, what metals are not magnetic to a magnet:
- paramagnetic materials: aluminum, platinum, chromium, magnesium, tungsten;
- diamagnetic materials: copper, gold, silver, zinc, mercury, cadmium, zirconium.
In general, we can say that ferrous metals are attracted to a magnet, non-ferrous metals are not.
If we talk about alloys, then iron alloys are magnetic. These primarily include steel and cast iron. Precious coins can also be attracted to a magnet, since they are not made of pure non-ferrous metal, but of an alloy that may contain a small amount of ferromagnetic material. But jewelry made of pure non-ferrous metal will not be attracted to a magnet.
What metals do not rust and are not magnetic? These are ordinary food grade stainless steel, gold and silver items.
Source: https://FB.ru/article/435941/kakie-metallyi-ne-magnityatsya-i-pochemu
Why do magnets demagnetize - Metals and their processing
Employees of the site p-magnit.ru are sometimes asked about how to make a neodymium magnet with your own hands. Let's try to figure out how possible this is, and what the process of producing such products is all about.
So, the devices we sell consist of an alloy that is 70% iron and almost 30% boron. Only a fraction of a percent in its composition is made up of the rare earth metal neodymium, natural deposits of which are extremely rare in nature. Most of them are in China; they are found in only a few other countries, including Russia.
Before making neodymium magnets, manufacturers create molds for them from sand. Then the tray with the molds is doused with gas and subjected to heat treatment, due to which the sand hardens and retains the future outlines of the metal workpiece on its surface. Hot metal will later be placed in these forms, from which, in fact, the necessary products will be obtained.
Now let's directly look at how a neodymium magnet is made. Unlike ferromagnetic products, the metal here is not melted, but sintered from a powder mixture placed in an inert or vacuum environment.
Then the resulting magnetoplast is pressed while simultaneously exposing it to an electromagnetic field of a certain intensity. As you can see, even at the initial stage of production, it is noticeable that the question of how to make neodymium magnets at home sounds inappropriate.
The operations and equipment used are too complex. Creating such conditions at home is hardly possible.
After the workpieces are removed from the molds, they are subjected to mechanical processing - they are carefully polished, then they are fired to improve the coercive force of the products.
Finally, we come to the last steps, which will help to finally answer the question of how neodymium magnets are made. The sintered NdFeB alloy is again machine-finished using a special tool. During operation, a cooling lubricant is used to prevent overheating or ignition of the powder.
A protective coating is applied to the magnets. This is due, firstly, to the fact that sintered metals are quite fragile and need to be strengthened, and, secondly, the metal will be protected from corrosion processes and other environmental influences.
So manufacturers worry in advance about how to make a neodymium magnet stronger and more durable. The coating can be copper, nickel, zinc. In the last phase of the production process, magnetization is applied through a strong magnetic field.
Then they are sent to the warehouse, and from there to customers.
So, after we examined the production process in more or less detail, it became clear that we probably shouldn’t seriously ask the question “how to make a neodymium magnet at home.” After all, this requires not only certain knowledge, but many complex units.
How to completely demagnetize a neodymium magnet
Neodymium magnets are very popular in modern industry and in solving a number of everyday problems. If the buyer (for example) chose strong magnets for delivery in St. Petersburg, but violated the storage or transportation conditions, as a result of which they stuck together, it may be necessary to carry out a demagnetization procedure. The same action may be necessary in other cases when it is necessary for the product to lose its qualities.
The process can be carried out in various ways, including using factory equipment, and it is necessary to decide how to demagnetize a neodymium magnet taking into account your capabilities.
Methods for demagnetizing a magnet
Loss of the ability to attract metal objects can occur both naturally and during a number of actions. Subject to the rules of operation and storage, the qualities of neodymium elements are maintained for 100 years or more, and ferrite analogues continue to attract metal for 8-10 years. Degaussing neodymiums naturally is not practical if the procedure is to be performed on a new item.
THIS IS INTERESTING: Magnets for welding
Product heating
This method is used both in industrial and domestic conditions: if the magnet is made of a standard alloy of neodymium with boron and iron, it will lose its properties when placed in water boiling at 80 degrees Celsius or in case of contact with a surface heated to the specified temperature.
If we are talking about a product with increased resistance to thermal shocks, it is unlikely that it will be possible to perform the procedure at home: the demagnetization temperature of neodymium magnets with such properties is 200 degrees Celsius.
To carry out the procedure in such cases, special industrial equipment is used.
Mechanical Actions
Neodymium can lose its qualities as a result of a strong directed impact, for example, an impact: this material has a powder structure that is destroyed when dropped from a height or when exposed to impact equipment. In addition, demagnetization can occur accidentally during the process of drilling or cutting a magnet: this is due to excessive mechanical pressure or an increase in the temperature of the product without forced cooling.
Treatment with external magnetic influence
Most often, if it is possible to use industrial equipment of increased power, another magnet is used, which allows the formation of a field with an induction force of about 4 Tesla. A neodymium magnet is demagnetized in a matter of seconds, so this method, despite its technological complexity, is characterized by the fastest possible result.
How to magnetize demagnetized neodymium
If the demagnetization of an element occurs accidentally, and it is necessary to return the product to its properties, it is impossible to do this at home. Restoring a neodymium magnet requires the use of a product that can create a very powerful field, and this requires the use of professional equipment used to create such items.
Usually, if you need to return the magnetization properties for a specific element, you contact a factory that specializes in the production of such products.
Is there anything I can do to make the magnet stronger?
If neodymium used for household purposes has become demagnetized, often a more appropriate solution would be to purchase a new element. The cost of magnetization work varies depending on the required properties and pricing policy of a particular production.
Application of neodymium magnet
These products are available in various shapes and sizes and are used for the following tasks:
- Creating a clamping effect, fixing metal elements to each other. Using neodymium magnets, you can attach an antenna, license plate, plate, other metal part, device or entire mechanism.
- Filtration of oil systems in cars and other equipment: neodymium magnets allow you to easily and quickly remove metal shavings.
- Creation of magnetic locks and fasteners used in industrial sectors and household purposes.
- Search work related to the search for metal objects (search for treasures, historical values, weapons, mine clearance work, etc.).
- Restoring other magnetic elements: using a neodymium element, you can create a magnetic field that will return the product to its ability to attract metal.
- Deleting information recorded on floppy disks, disks, flash drives and other electronic media for security purposes.
- Creation of devices for universal use (hangers, stirring devices, compasses, etc.).
- Construction of current generators that can be used as experimental models or devices suitable for domestic use.
- Making jewelry: Neodymium can come in different shapes and sizes, and beads made from this material are often given a chrome finish and can be painted in different colors.
- Treatment of water using magnetic influence, as a result of which the formation of scale is reduced, and the liquid itself acquires an improved taste and smell.
- Fuel conditioning, which allows you to reduce fuel consumption for cars and motorcycles.
- Sorting small metal items that need to be removed from a variety of non-metal items.
THIS IS INTERESTING: Is copper magnetic or not?
Conclusion
Neodymium magnets are products that are widely used in commercial, industrial and household applications, they are characterized by high load capacity, excellent attractive properties and durability.
Before demagnetizing neodymium magnets, it is important to make sure that you have the necessary equipment: this requires either an industrial installation or a device for heating to at least 80 degrees.
Magnetizing products that have lost their quality is rarely advisable, but if necessary, you can order the procedure by contacting the manufacturer.
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Source: https://magnetline.ru/metally-i-splavy/pochemu-magnity-razmagnichivayutsya.html
Why putting a magnet on a meter is a bad idea
To reduce water and electricity bills, some people put powerful magnets on their meters. Under the influence of a magnetic field, even during the consumption of water and light, the device does not rotate.
But a magnet is not an innocent way to save money. If a person uses water and electricity, but does not pay for them, he steals, that is, he commits an administrative offense. In the laws, this is called theft and is punishable by a fine, temporary arrest or community service.
Inspectors will probably know about the magnet
It seems that if you install a magnet only occasionally and pay a little on the bills, then no one will know about the violation. But inspectors have several ways to detect theft:
- See the magnet. Usually they try not to let the inspectors in or quickly remove the magnet before opening the doors. But it may happen that the person who placed it will not be at home, the door will be opened by a child or a grandmother who has come to stay, or the residents will simply forget about the magnet. Then the inspector will take a photo of the violation and draw up a report, and then you will be issued a fine.
- Check the indicator. Modern water and light meters have special indicators, or magnetic field sensors. It is enough to bring a powerful magnet to the meter once - and the indicator will change color forever. And some of the most modern devices can even send a message to the dispatcher, so they will instantly know about the magnet.
- Measure the magnetic field. If a magnet has recently been placed on the meter, the magnetic field around it will be abnormally large. It can be measured using a special device - a Teslameter. And if the indicator can sometimes somehow be fooled, then the Teslameter cannot be fooled: it will clearly indicate that there was a magnet on the meter.
The Teslameter is expensive and is still rarely used, but gradually this method is becoming more and more popular. You can especially often find inspectors with teslameters in Moscow and St. Petersburg.
To record a violation and draw up a report, inspectors must come to the meter in person. To do this, management companies (MCs) arrange scheduled inspections every 1–2 years. Theoretically, you can adapt to them and use the magnet only immediately after the inspectors’ visit in order to save at least a little.
But if according to the general building meter the resource consumption is the same, but according to the sum of the apartment meters it is significantly less, this indicates theft on the part of the residents. In this case, the management company can arrange an unscheduled inspection and detect the magnet.
You will be punished for installing a magnet
Most often, on the basis of Government Resolution No. 354, they are required to pay the cost of resources tenfold. The cost is calculated according to average standards and multiplied by the time that has passed since the last inspection, but by a maximum of 3 months.
That is, if you install a magnet and it is discovered in six months, you will be forced to pay 10 times more than you would pay according to the standards for three months. Standards, by the way, are often too high.
Usually people spend less than the average per month, so the overpayment will be large.
This fine is not related to theft - it only relates to violation of the meter. If the Criminal Code decides to sue, the violator faces the following penalties:
- A fine of 10–15 thousand rubles for the unauthorized use of electrical, thermal energy, oil or gas, according to the Administrative Code.
- A fine of five times the value of the stolen property for petty theft up to 1 thousand rubles, according to the Administrative Code.
- A fine for petty theft is from 1 to 2.5 thousand rubles in the amount of five times the value of the stolen property, or arrest for 10–15 days, or up to 120 hours of community service.
Theoretically, when more than 2.5 thousand rubles are stolen, the crime is no longer considered administrative, but criminal. He faces a fine of up to 300 thousand rubles or imprisonment for 1–2 years. But in fact, such punishments are not imposed in the Russian Federation for magnets on meters.
You can save money without a magnet
To save money, you don't need to install a magnet. There are several legal ways to pay much less for electricity and water:
- Use LED lamps. They consume 8–10 times less electricity than conventional ones.
- Turn off the water when you are not using it. This is useful to do even in small things, such as while brushing your teeth or in the shower while you lather up.
- Always turn off the lights when leaving a room. You can install motion sensors so that the lights turn on and off automatically.
- Install aerators on taps. They break the stream into small droplets, which creates greater pressure but reduces water consumption.
- Use a washing machine and dishwasher. They use less water than hand washing or washing, and they also use cheaper cold water rather than hot water. Electricity consumption increases, but the final payment decreases.
- Fix all leaks in a timely manner.
- If the tank has one flush mode, place a bottle filled with water in it. This will slightly reduce the volume of the tank. There will still be enough water to rinse, but the consumption will decrease.
- Install a tank with two flush modes to waste less water.
- If cold water flows for a long time before hot water, you can drain it into a bucket. Then the water can be used for flushing, watering plants or other purposes.
Reasonable consumption of resources will help you save money even without magnets, so you don’t have to fear inspections and fines.
Source: https://Lifehacker.ru/magnit-na-schyotchik/
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles. Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other.
The north pole of one magnet repels the north pole of the other. The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road. For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the atom around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction.
That is, each domain is a small magnet. Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if you manage to orient the domains in one direction so that the forces of the magnetic fields combine, then beware! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Magnetic iron ore mineral is a natural magnet. But still, most magnets are made artificially. What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field.
As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet. You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large neodymium magnet.
Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Why doesn't a magnet attract everything?
In fact, the interaction of a magnet with substances has many more options than just “attracts” or “does not attract.” Iron, nickel, and some alloys are metals that, due to their specific structure, are very strongly attracted by a magnet.
The vast majority of other metals, as well as other substances, also interact with magnetic fields - they are attracted or repelled by magnets, but only thousands and millions of times weaker.
Therefore, in order to notice the attraction of such substances to a magnet, you need to use an extremely strong magnetic field, which you cannot get at home.
But since all substances are attracted to a magnet, the original question can be reformulated as follows: “Why then is iron so strongly attracted by a magnet that manifestations of this are easy to notice in everyday life?” The answer is: it is determined by the structure and bonding of iron atoms. Any substance is composed of atoms connected to each other by their outer electron shells.
It is the electrons of the outer shells that are sensitive to the magnetic field; they determine the magnetism of materials. In most substances, the electrons of neighboring atoms feel the magnetic field “at random” - some repel, others attract, and some generally try to turn the object around.
Therefore, if you take a large piece of a substance, then its average force of interaction with a magnet will be very small.
Iron and metals similar to it have a special feature - the connection between neighboring atoms is such that they sense the magnetic field in a coordinated manner. If a few atoms are tuned to be attracted to a magnet, they will cause all neighboring atoms to do the same. As a result, in a piece of iron all the atoms “want to attract” or “want to repel” at once, and because of this, a very large force of interaction with the magnet is obtained.
A magnet is a body that has its own magnetic field. In a magnetic field, there is some effect on external objects that are nearby, the most obvious being the ability of a magnet to attract metal.
The magnet and its properties were known to both the ancient Greeks and the Chinese. They noticed a strange phenomenon: small pieces of iron were attracted to some natural stones.
This phenomenon was first called divine and used in rituals, but with the development of natural science it became obvious that the properties were of a completely earthly nature, which was first explained by the physicist from Copenhagen Hans Christian Oersted.
He discovered in 1820 a certain connection between the electric discharge of current and a magnet, which gave rise to the doctrine of electric current and magnetic attraction.
Natural science research
Natural science research
Oersted, conducting experiments with a magnetic needle and a conductor, noticed the following feature: a discharge of energy directed towards the needle instantly acted on it, and it began to deviate.
The arrow always deviated, no matter from which side he approached.
A physicist from France, Dominique François Arago, began repeated experiments with a magnet, using as a basis a glass tube rewound with a metal thread, and he installed an iron rod in the middle of this object.
With the help of electricity, the iron inside began to be sharply magnetized, because of this various keys began to stick, but as soon as the discharge was turned off, the keys immediately fell to the floor.
Based on what was happening, a physicist from France, Andre Ampere, developed an accurate description of everything that happened in this experiment.
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear. If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines). Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Magnetic effect
Magnetic effect
Today it is obvious that the matter is not in miracles, but in a more than unique characteristic of the internal structure of the electronic circuits that form magnets. An electron that constantly rotates around an atom forms the same magnetic field.
Microatoms have a magnetic effect and are in complete equilibrium, but magnets, with their attraction, influence some types of metals, such as iron, nickel, cobalt.
These metals are also called ferromagnets. In close proximity to a magnet, atoms immediately begin to rearrange and form magnetic poles.
Atomic magnetic fields exist in an ordered system; they are also called domains. In this characteristic system there are two poles opposite to each other - north and south.
Application
IT News
Date Category: Physics
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
- Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear.
- If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines).
- Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Source: https://Information-Technology.ru/sci-pop-articles/23-physics/231-pochemu-magnit-prityagivaet-zhelez
Difference between neodymium magnet and ordinary magnet
The main difference between neodymium magnet and ordinary magnet is that neodymium magnet contains neodymium, iron and boron as the key chemical elements, while ordinary magnet contains iron as the main chemical element.
A neodymium magnet is a type of magnet with strong magnetism made from rare earth elements such as neodymium. It is an alloy of several metals such as iron, boron, etc. Whereas, conventional magnets are ceramic magnets which contain ferrite as the main compound. It contains a high percentage of iron(III) oxide along with some other metals such as barium. These magnets are popular due to their low cost and fairly high magnetism strength.
- Overview and main differences
- What is a neodymium magnet
- What is a regular magnet
- What is the difference between a neodymium magnet and a regular magnet
- Conclusion
What is a neodymium magnet?
A neodymium magnet is a type of rare earth magnet that contains neodymium, iron and boron. This is a permanent magnet. It has an alloy of these metals in the form of a tetragonal crystal structure Nd2Fe14B. This magnet is the strongest commercial grade magnet currently available. Therefore, these magnets can replace many other types of magnets in modern products such as motors in cordless tools.
Neodymium is a ferromagnetic material; so we can magnetize it so that it becomes a magnet. However, the Curie temperature (the material at which a magnet loses magnetism) of this element is very low. Therefore, in its pure form it exhibits magnetism at very low temperatures. But if we make an alloy of neodymium with some transition metals such as iron, we can improve the magnetism of this material. This is a “neodymium magnet”.
Neodymium magnetic balls
There are several factors that determine the strength of this magnet. The main factor is the tetragonal crystal structure of this alloy.
In addition, the neodymium atom also has a significant magnetic dipole moment due to the presence of 4 unpaired electrons.
In addition to this, these magnets have exceptionally high residual coefficient (magnetic field strength), coercivity (material's resistance to demagnetization) and magnetic energy density. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively low.
What is a regular magnet?
Regular magnets are magnets that we use for common purposes. In most cases we use ceramic (or ferrite) magnets. These magnets contain ferrite as the main component. Ferrite is a ceramic material. It is mainly composed of iron(III) oxide. and there are also some other metals such as barium, manganese, nickel and zinc. These components are ferromagnetic and electrically non-conductive.
Ceramic magnets
In addition, these magnets have a relatively low residual magnetic induction (magnetic field strength) and coercive force (material resistance to demagnetization). But there are two types of ferrite magnets: hard ferrites and soft ferrites depending on the coercivity (high and low respectively). The magnetic energy density is also very low. But the Curie temperature (the material at which the magnet loses its magnetism) is relatively high.
Source: https://raznisa.ru/raznica-mezhdu-neodimovym-magnitom-i-obychnym-magnitom/
How a magnet affects us: the whole truth about magnetic jewelry
Nowadays, treatment is mainly based on medications. Pharmacy shelves are filled with various tablets, capsules, syrups and drops.
In addition to their beneficial effect, they have many side effects on the body: they overload the liver and kidneys, and negatively affect the immune system. In addition, they are addictive, so when their therapeutic effect is needed most, there is no need to wait for it.
Of course, we are mainly talking about patients with chronic pathology, which requires constant monitoring and correction of the condition, and systematic use of medications.
In order to relieve the body of medications, but at the same time “keep the disease in check,” more and more doctors are trying to dilute the treatment with physiotherapy. There are many similar techniques, each with its own vectors of work. In this article we will take a closer look at magnetic therapy.
History of magnetic therapy
Magnetotherapy is a physiotherapeutic technique based on the effect of a magnetic field on the human body.
Since ancient times, people have been interested in magnetic fields. Their existence was first noticed about 2 thousand years ago. Over time, it found practical application in the form of a compass. According to historical documents, it was first noticed in China 1 thousand years before the new era that a long piece of magnetic iron attached to a plug floating in a liquid pointed north.
Since then, people began to find new uses for this important invention. Without it, it would have been impossible to create cars, ships, tape recorders, etc. In medicine, the magnet also played an undeniable role.
Doctors of ancient times (immediately after the discovery of the properties of a magnet) began to study its effect on the human body. Initially, data on its properties for humans were contradictory. Some considered the magnet a potent poison, while others considered it a panacea. The history of medicine knows many cases of the use of magnets as a remedy:
- Hippocrates used magnetic powder as a laxative.
- Cleopatra constantly wore a magnetic necklace, which was supposed to preserve her beauty and youth.
- Queen Elizabeth I suffered from arthritis. According to the documents, she was treated with magnets.
- Franz Antoine Mesmer cured many people using magnets. He successfully practiced in Vienna and Paris, where, as part of the team of the Royal Society of Medicine, he tried to use this technique to heal people with seizures and nervous diseases. They used magnets in the form of rings, bracelets, and amulets. After conducting many experiments, Mesmer came to the conclusion that our body is surrounded by a magnetic field, and direct influence on it can help cure many diseases.
- After the Civil War, there was a real shortage of qualified medical personnel in the United States. This led to the spread of folk remedies. Magnets were especially popular. They were used in the form of insoles, bandages, and rings. They have been successfully used as a pain reliever.
- At the beginning of the 19th century, more and more articles began to appear scientifically substantiating the use of magnetic therapy.
Nowadays, this type of physiotherapy has become especially widespread in the USA, China, and Japan. Many means, methods and types of magnetic therapy have been developed, which are successfully used in various branches of medicine.
Scientific rationale for magnetic therapy
How and why does it work? How can a small bracelet help you cure a huge list of diseases?
Thanks to physics, we know that everything in the world has its own magnetic fields. Man is no exception. Our magnetic field is formed due to the flow of blood through the vessels. It consists of metal ions, which, when circulating, form a static magnetic field. It is present where there are blood vessels in our body, that is, absolutely everywhere.
When we are exposed to a magnetic field, electric currents are generated in the body. Because of this, a number of changes occur:
- changes in the configuration of cell membranes and their structural units (lysosomes, mitochondria, etc.);
- changes in cell membrane permeability;
- changes in the course of chemical reactions in the body that occur with the participation of free radicals (almost all processes in which enzymes are involved);
- changes in the physicochemical properties of all body fluids;
- reorientation of large molecules (including proteins, fats, carbohydrates).
By influencing these basic processes in the body, you can regulate its condition. Currently, many studies have been conducted that confirm the effectiveness of magnetic therapy. They make it possible to become an alternative to heavy medication load.
Types of magnetic therapy
Thanks to technological progress, several types of magnets are available to us that can be used for therapeutic purposes. Magnetic therapy is differentiated based on the type of magnetic fields: variable and constant. There is also a distinction between general magnetic therapy (when the effect occurs on the entire body as a whole) and local (the effect is carried out locally: on a joint, a separate organ or area).
If we talk about technical equipment, there are now three main types of devices available:
- Stationary. It consists of a table, a magnet and a computer, which contains several basic treatment protocols. The patient lies down on the table, and the physiotherapist selects the necessary protocol. The device can also be equipped with additional components (a magnet for local, directional influence, a belt, a solenoid that allows you to create a circular magnetic field). Treatment usually takes place in courses. One session lasts from 15 to 40 minutes. No special preparation is required. The only recommendation is to drink a glass of water before the procedure to slightly enhance the effect of the device.
- Portable. It is a device that the patient can easily carry with him. The effect is carried out by applying the device to the affected area of the body or wearing it in this area. The most popular device is considered to be “Magofon-01”, which creates special vibroacoustic vibrations and a low-frequency magnetic field. This type of device has pronounced analgesic, anti-edematous and anti-inflammatory effects.
- Magnetic jewelry. Patients wishing to purchase magnetic jewelry have a wide range of choices: rings, bracelets, necklaces, watches, earrings, brooches, etc. They are often elegantly and tastefully made. Naturally, it is difficult to suspect a medicinal product in these accessories. They are usually made of copper, metal, or jewelry steel. Active magnets are placed on their inner surface. It is the latter that have a special field; accordingly, they are made with extreme care in order to help and not harm a person.
The impact of magnetic jewelry on the human body
Magnets change our state at the molecular level. This affects the organs and their performance, which allows doctors to recommend them as an additional treatment for a number of pathologies.
The main beneficial therapeutic effects of magnetic jewelry include:
- Improving microcirculation. Blood circulation under the influence of magnetic fields improves throughout the body, including blood circulation in the brain. This effect is realized due to an increase in the lumen of the smallest vessels in our body - capillaries. At the same time, the speed of blood flow in vessels of medium and large caliber is optimized.
- Reduced blood viscosity. This effect helps prevent the formation of blood clots.
- Improving the permeability of the vascular wall. It also optimizes blood flow while slowly clearing cholesterol deposits from the blood vessels.
- Normalization of lymphatic drainage. Magnetic fields have a beneficial effect on lymphatic vessels, expanding their lumen. This promotes better lymph outflow, reducing tissue swelling and accelerating the process of removing by-products of metabolic processes.
- Stimulation of tissue nutrition. This implies that tissues begin to receive more nutrients when using magnetic jewelry. Metabolism at the cellular level is enhanced, which improves recovery and regeneration processes in the body.
- Anti-inflammatory effect. Reducing swelling, improving blood circulation in organs and optimizing the synthesis of anti-inflammatory substances (prostaglandins) contributes to a faster resolution of inflammatory processes in the body.
- Regulation of the nervous system. This technique allows you to activate the processes of excitation or inhibition of the nervous system, depending on the type of magnetic therapy and the point of application.
- Decreased sensitivity of pain receptors. The impact on this type of receptor allows magnetic jewelry to realize an analgesic effect. In addition, there are studies that clearly demonstrate that magnetic fields can lead to the regeneration of nerve fibers and improve the conduction of impulses through them.
For what diseases are magnetic jewelry recommended?
Considering these effects of magnetic jewelry, it is advisable to use them for diseases such as:
Pathology of the cardiovascular system |
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Pathology of the nervous system |
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Diseases of the bronchopulmonary system and ENT organs |
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Diseases of the musculoskeletal system |
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Diseases of the gastrointestinal tract |
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Pathology of the urinary and reproductive system |
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Oral diseases |
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Pathologies of the visual analyzer |
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Skin diseases |
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Endocrine system |
|
Source: https://fitexpert.biz/magnity/
Why does a magnet attract - all about magnetic fields
Why does a magnet attract?
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles.
Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other. The north pole of one magnet repels the north pole of the other.
Magnetic and electric current
The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
Magnetic field lines
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road.
For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
Related materials:
Gravitational interaction
Electron movement and magnetic field
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the electron around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
Why materials are magnetic and not magnetic
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction. That is, each domain is a small magnet.
Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if we manage to orient the domains in one direction so that the forces of the magnetic fields add up, then watch out! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Interesting fact: the mineral iron ore is a natural magnet. But still, most magnets are made artificially.
What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field. As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet.
Related materials:
How are magnets made?
You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large horseshoe magnet. Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Source: https://kipmu.ru/pochemu-magnit-prityagivaet-ili-vse-o-magnitnyx-polyax/
Neodymium magnet: what does it mean and what is it made of, how to use
Neodymium magnet is the most powerful and permanent magnet, which contains rare earth neodymium, boron and iron. What is the complete definition of a magnet and its main advantages, what is its strength and what is its principle of operation? More on this later.
What it is
A neodymium magnet is a magnetic element that is composed of neodymium rare earth boron and iron material. It has a crystal structure, tetragonal shape and formula Nd2Fe14B.
Neodymium magnet is the most common type
It was first created by General Motors in 1982. It is the strongest permanent magnetic element, the power of which is several times greater than usual. Equipped with a large magnetic induction of 12,400 gauss.
Note! This is a brittle alloy with the formula NdFeB, as well as a hard nickel-plated protective layer and the corresponding class. It is very popular and comes in various forms.
Full material definition
Advantages
The most common neodymium magnet is one that has an iron oxide alloy, which has good heat resistance, high magnetic permeability and low cost. Equipped with color coding, high coercivity, powerful magnetic field to hold objects suspended, compact size, light weight, affordable and wide range of applications. Has a long service life.
If an ordinary magnet works for 10 years and can be demagnetized, then a neodymium magnet does not lose its properties after 100 years. Another advantage is the shape. This product has a horseshoe shape. It gives the device a long service life. As for the cost, these are expensive products, but the cost is justified by excellent performance and impeccable reliability.
Durability of work as one of the advantages
Force
It is worth pointing out that the strength contained in neodymium magnets is another advantage. She is tall and it is impossible to find a competitor to her. This is a record type of indicator, the increase of which is impossible. Power is generated during manufacturing. Magnetization occurs after the alloy is formed. Thanks to existing technologies, the alloy is magnetized in such a way that the magnet has incredibly high power and this figure reaches a record.
Note! Power is a relative philistine concept. The force is stable, but it is measured using instruments. In this case, the readings depend on the thickness of the surface and cleanliness. The separation angle can have some influence.
Strength as one of the advantages
Life time
The service life of the equipment, if used properly, is 30 years. Due to careless handling, the device may be damaged. The point is the lack of flexibility, as well as brittleness and cracking under heavy load. Falls, impacts, or reduced traction will reduce the life of the equipment. For this reason, it is necessary to avoid falls using parts that come into contact during movements.
Another extremely important point is the irreversible loss of magnetic properties due to heating. Therefore, grinding with cutting or drilling reduces the chain force and may ignite the alloy. If storage and operation are organized correctly, then magnetization is maintained for 10 years.
Long service life
Design
When answering the question of what a neodymium magnet is made of, we can point out that it is a rare earth element that contains an atom with lanthanide or actinide. The classic composition may still contain an additive.
It is used to increase strength with endurance and resistance to high temperatures. Boron is used in small quantities, iron is a binding element. Thanks to this composition, greater adhesion is obtained.
When connecting several ferrite rings, you can separate them with your hands. As for neodymium magnets, this cannot be done.
Composition of magnetic material
How are neodymium magnets magnetized?
The magnetization of neodymium magnets occurs through the interaction of bromine ions, iron and neodymium in a powerful magnetic field. Thanks to such actions, an element is obtained that has a high coercive force and high adhesion power. It also has an extremely long service life in everyday life.
Magnetization of neodymium materials
Principle of operation
A neodymium magnet works very simply. If two magnetic elements are connected and the poles coincide in direction, the magnetic force of the two fields will be enhanced. The result is an overall strong magnetic field. With the reverse arrangement of the magnetized elements, the magnetic field will be suppressed.
Principle of operation
How to use
Neodymium magnetic element is the strongest, exceeding analogues that are based on rare earth metal. In addition, neodymium is capable of maintaining a magnetized structure for a significantly long time. Such equipment can be used in various fields. For example, it is used in the manufacture of over-ear headphones with wind generators, motor wheels and scooters.
Note! Magnets are actively used in industrial, household, and medical fields. They are also used to carry out search work with a metal detector. They can often be found in plumbing fixtures or souvenirs.
Specific examples include the use of magnets in the development of medical devices, magnetic treatment of water, the creation of oil and technological filters, and the formation of actuators with highly sensitive sensors. In addition, they are needed to produce clothes with covers and shoes, and to create advertising, information and navigation materials.
Scope of application of the material
Overall, neodymium is the most powerful permanent magnetic material that has high resistance to demagnetization, attractive power, and a metallic appearance. It has a long service life and consists of boron, iron and a metal of the lanthanide group.
Source: https://rusenergetics.ru/polezno-znat/neodimovykh-magnitakh
Permanent magnets, their description and principle of operation:
Along with pieces of amber electrified by friction, permanent magnets were for ancient people the first material evidence of electromagnetic phenomena (lightning at the dawn of history was definitely attributed to the sphere of manifestation of immaterial forces).
Explaining the nature of ferromagnetism has always occupied the inquisitive minds of scientists, however, even now the physical nature of the permanent magnetization of some substances, both natural and artificially created, has not yet been fully revealed, leaving a considerable field of activity for modern and future researchers.
Traditional materials for permanent magnets
They have been actively used in industry since 1940 with the advent of alnico alloy (AlNiCo). Previously, permanent magnets made of various types of steel were used only in compasses and magnetos. Alnico made it possible to replace electromagnets with them and use them in devices such as motors, generators and loudspeakers.
This penetration into our daily lives received a new impetus with the creation of ferrite magnets, and since then permanent magnets have become commonplace.
The revolution in magnetic materials began around 1970, with the creation of the samarium-cobalt family of hard magnetic materials with previously unheard-of magnetic energy densities.
Then a new generation of rare earth magnets was discovered, based on neodymium, iron and boron, with a much higher magnetic energy density than samarium cobalt (SmCo) and at an expectedly low cost.
These two families of rare earth magnets have such high energy densities that they can not only replace electromagnets, but be used in areas that are inaccessible to them. Examples include the tiny permanent magnet stepper motor in wristwatches and the sound transducers in Walkman-type headphones.
The gradual improvement in the magnetic properties of materials is shown in the diagram below.
Neodymium permanent magnets
They represent the latest and most significant development in this field over the past decades. Their discovery was first announced almost simultaneously at the end of 1983 by metal specialists from Sumitomo and General Motors. They are based on the intermetallic compound NdFeB: an alloy of neodymium, iron and boron. Of these, neodymium is a rare earth element extracted from the mineral monazite.
The enormous interest that these permanent magnets have generated arises because for the first time a new magnetic material has been produced that is not only stronger than the previous generation, but is more economical.
It consists mainly of iron, which is much cheaper than cobalt, and neodymium, which is one of the most common rare earth materials and has more reserves on Earth than lead.
The major rare earth minerals monazite and bastanesite contain five to ten times more neodymium than samarium.
Physical mechanism of permanent magnetization
To explain the functioning of a permanent magnet, we must look inside it down to the atomic scale. Each atom has a set of spins of its electrons, which together form its magnetic moment.
For our purposes, we can consider each atom as a small bar magnet. When a permanent magnet is demagnetized (either by heating it to a high temperature or by an external magnetic field), each atomic moment is oriented randomly (see Fig.
below) and no regularity is observed.
When it is magnetized in a strong magnetic field, all atomic moments are oriented in the direction of the field and, as it were, interlocked with each other (see figure below). This coupling allows the permanent magnet field to be maintained when the external field is removed, and also resists demagnetization when its direction is changed. A measure of the cohesive force of atomic moments is the magnitude of the coercive force of the magnet. More on this later.
In a more in-depth presentation of the magnetization mechanism, one does not operate with the concepts of atomic moments, but uses ideas about miniature (of the order of 0.001 cm) regions inside the magnet, which initially have permanent magnetization, but are randomly oriented in the absence of an external field, so that a strict reader, if desired, can attribute the above physical The mechanism is not related to the magnet as a whole. but to its separate domain.
Induction and magnetization
The atomic moments are summed up and form the magnetic moment of the entire permanent magnet, and its magnetization M shows the magnitude of this moment per unit volume. Magnetic induction B shows that a permanent magnet is the result of an external magnetic force (field strength) H applied during primary magnetization, as well as an internal magnetization M due to the orientation of atomic (or domain) moments. Its value in the general case is given by the formula:
B = µ0 (H + M),
where µ0 is a constant.
In a permanent ring and homogeneous magnet, the field strength H inside it (in the absence of an external field) is equal to zero, since, according to the law of total current, the integral of it along any circle inside such a ring core is equal to:
H∙2πR = iw=0, whence H=0.
Therefore, the magnetization in a ring magnet is:
M = B/µ0.
In an open magnet, for example, in the same ring magnet, but with an air gap of width lzaz in a core of length lser, in the absence of an external field and the same induction B inside the core and in the gap, according to the law of total current, we obtain:
Hser l ser + (1/ µ0)Blzaz = iw=0.
Since B = µ0(Hser + Mser), then, substituting its expression into the previous one, we get:
Hser(l ser + lzaz) + Mser lzaz=0,
or
Hser = ─ Mser lzaz(l ser + lzaz).
In the air gap:
Hzaz = B/µ0,
wherein B is determined by the given Mser and the found Hser.
Magnetization curve
Starting from the unmagnetized state, when H increases from zero, due to the orientation of all atomic moments in the direction of the external field, M and B quickly increase, changing along section “a” of the main magnetization curve (see figure below).
When all atomic moments are equalized, M comes to its saturation value, and a further increase in B occurs solely due to the applied field (section b of the main curve in the figure below).
When the external field decreases to zero, the induction B decreases not along the original path, but along section “c” due to the coupling of atomic moments, tending to maintain them in the same direction. The magnetization curve begins to describe the so-called hysteresis loop.
When H (external field) approaches zero, the induction approaches a residual value determined only by atomic moments:
Br = μ0 (0 + Mg).
After the direction of H changes, H and M act in opposite directions and B decreases (part of the curve “d” in the figure). The value of the field at which B decreases to zero is called the coercive force of the BHC magnet.
When the magnitude of the applied field is large enough to break the cohesion of the atomic moments, they are oriented in the new direction of the field, and the direction of M is reversed. The field value at which this occurs is called the internal coercive force of the permanent magnet MHC.
So, there are two different but related coercive forces associated with a permanent magnet.
The figure below shows the basic demagnetization curves of various materials for permanent magnets. It shows that NdFeB magnets have the highest residual induction Br and coercive force (both total and internal, i.e., determined without taking into account the strength H, only by the magnetization M).
Surface (ampere) currents
The magnetic fields of permanent magnets can be considered as the fields of some associated currents flowing along their surfaces. These currents are called Ampere currents. In the usual sense of the word, there are no currents inside permanent magnets.
However, comparing the magnetic fields of permanent magnets and the fields of currents in coils, the French physicist Ampere suggested that the magnetization of a substance can be explained by the flow of microscopic currents, forming microscopic closed circuits.
And indeed, the analogy between the field of a solenoid and a long cylindrical magnet is almost complete: there is a north and south pole of a permanent magnet and the same poles of the solenoid, and the patterns of force lines of their fields are also very similar (see figure below).
Are there currents inside a magnet?
Let's imagine that the entire volume of a bar permanent magnet (with an arbitrary cross-sectional shape) is filled with microscopic Ampere currents. A cross section of a magnet with such currents is shown in the figure below. Each of them has a magnetic moment. With the same orientation in the direction of the external field, they form a resulting magnetic moment that is different from zero.
It determines the existence of a magnetic field in the apparent absence of ordered movement of charges, in the absence of current through any cross section of the magnet. It is also easy to understand that inside it, the currents of adjacent (contacting) circuits are compensated. Only the currents on the surface of the body, which form the surface current of a permanent magnet, are uncompensated.
Its density turns out to be equal to the magnetization M.
How to get rid of moving contacts
The problem of creating a contactless synchronous machine is known. Its traditional design with electromagnetic excitation from the poles of a rotor with coils involves supplying current to them through movable contacts - slip rings with brushes.
The disadvantages of such a technical solution are well known: they are difficulties in maintenance, low reliability, and large losses in moving contacts, especially when it comes to powerful turbo and hydrogen generators, the excitation circuits of which consume considerable electrical power.
If you make such a generator using permanent magnets, then the contact problem immediately goes away. However, there is a problem of reliable fastening of magnets on a rotating rotor. This is where the experience gained in tractor manufacturing can come in handy. They have long been using an inductor generator with permanent magnets located in rotor slots filled with a low-melting alloy.
Permanent magnet motor
In recent decades, DC motors have become widespread. Such a unit consists of the electric motor itself and an electronic commutator for its armature winding, which performs the functions of a collector.
The electric motor is a synchronous motor with permanent magnets located on the rotor, as in Fig. above, with a stationary armature winding on the stator.
Electronic switch circuitry is an inverter of direct voltage (or current) of the supply network.
The main advantage of such a motor is its non-contact nature. Its specific element is a photo-, induction or Hall rotor position sensor that controls the operation of the inverter.
Source: https://syl.ru/article/203617/new_postoyannyie-magnityi-ih-opisanie-i-printsip-deystviya
What metals are not magnetic and why?
Any child knows that metals are attracted to magnets. After all, they have more than once hung magnets on the metal door of the refrigerator or letters with magnets on a special board. However, if you put a spoon against a magnet, there will be no attraction. But the spoon is also metal, so why does this happen? So, let's find out which metals are not magnetic.
Scientific point of view
To determine which metals are not magnetic, you need to find out how all metals in general can relate to magnets and a magnetic field. With respect to the applied magnetic field, all substances are divided into diamagnetic, paramagnetic and ferromagnetic.
Each atom consists of a positively charged nucleus and negatively charged electrons. They move continuously, which creates a magnetic field. The magnetic fields of electrons in one atom can enhance or cancel each other, depending on the direction of their movement. Moreover, the following can be compensated:
- Magnetic moments caused by the movement of electrons relative to the nucleus are orbital.
- Magnetic moments caused by the rotation of electrons around their axis are spin moments.
If all magnetic moments are equal to zero, the substance is classified as diamagnetic. If only spin moments are compensated - to paramagnets. If the fields are not compensated, use ferromagnets.
Paramagnets and ferromagnets
Let's consider the option when each atom of a substance has its own magnetic field. These fields are multidirectional and compensate each other. If you place a magnet next to such a substance, the fields will be oriented in one direction. The substance will have a magnetic field, a positive and a negative pole.
Then the substance will be attracted to the magnet and can itself become magnetized, that is, it will attract other metal objects. For example, you can magnetize steel clips at home. Each one will have a negative and a positive pole, and you can even hang a whole chain of paper clips on a magnet.
Such substances are called paramagnetic.
Ferromagnets are a small group of substances that are attracted to magnets and are easily magnetized even in a weak field.
Diamagnets
In diamagnetic materials, the magnetic fields inside each atom are compensated. In this case, when a substance is introduced into a magnetic field, the movement of electrons under the influence of the field will be added to the natural movement of electrons. This movement of electrons will cause an additional current, the magnetic field of which will be directed against the external field. Therefore, the diamagnetic material will be weakly repelled from the nearby magnet.
So, if we approach the question from a scientific point of view, which metals are not magnetic, the answer will be – diamagnetic.
Distribution of paramagnets and diamagnets in the periodic table of Mendeleev elements
The magnetic properties of simple substances change periodically with increasing atomic number of the element.
Substances that are not attracted to magnets (diamagnets) are located mainly in short periods - 1, 2, 3. Which metals are not magnetic? These are lithium and beryllium, and sodium, magnesium and aluminum are already classified as paramagnetic.
Substances that are attracted to magnets (paramagnets) are located mainly in the long periods of the Mendeleev periodic system - 4, 5, 6, 7.
However, the last 8 elements in each long period are also diamagnetic.
In addition, three elements are distinguished - carbon, oxygen and tin, the magnetic properties of which are different for different allotropic modifications.
In addition, there are 25 more chemical elements whose magnetic properties could not be established due to their radioactivity and rapid decay or the complexity of synthesis.
The magnetic properties of lanthanides and actinides (all of which are metals) change irregularly. Among them there are para- and diamagnetic materials.
There are special magnetically ordered substances - chromium, manganese, iron, cobalt, nickel, the properties of which change irregularly.
What metals are not magnetic: list
There are only 9 ferromagnets, that is, metals that are highly magnetic, in nature. These are iron, cobalt, nickel, their alloys and compounds, as well as six lanthanide metals: gadolinium, terbium, dysprosium, holmium, erbium and thulium.
Metals that are attracted only to very strong magnets (paramagnetic): aluminum, copper, platinum, uranium.
Since in everyday life there are no such large magnets that would attract a paramagnetic material, and also no lanthanide metals are found, we can safely say that all metals except iron, cobalt, nickel and their alloys will not be attracted to magnets.
So, what metals are not magnetic to a magnet:
- paramagnetic materials: aluminum, platinum, chromium, magnesium, tungsten;
- diamagnetic materials: copper, gold, silver, zinc, mercury, cadmium, zirconium.
In general, we can say that ferrous metals are attracted to a magnet, non-ferrous metals are not.
If we talk about alloys, then iron alloys are magnetic. These primarily include steel and cast iron. Precious coins can also be attracted to a magnet, since they are not made of pure non-ferrous metal, but of an alloy that may contain a small amount of ferromagnetic material. But jewelry made of pure non-ferrous metal will not be attracted to a magnet.
What metals do not rust and are not magnetic? These are ordinary food grade stainless steel, gold and silver items.
Source: https://FB.ru/article/435941/kakie-metallyi-ne-magnityatsya-i-pochemu
Why do magnets demagnetize - Metals and their processing
Employees of the site p-magnit.ru are sometimes asked about how to make a neodymium magnet with your own hands. Let's try to figure out how possible this is, and what the process of producing such products is all about.
So, the devices we sell consist of an alloy that is 70% iron and almost 30% boron. Only a fraction of a percent in its composition is made up of the rare earth metal neodymium, natural deposits of which are extremely rare in nature. Most of them are in China; they are found in only a few other countries, including Russia.
Before making neodymium magnets, manufacturers create molds for them from sand. Then the tray with the molds is doused with gas and subjected to heat treatment, due to which the sand hardens and retains the future outlines of the metal workpiece on its surface. Hot metal will later be placed in these forms, from which, in fact, the necessary products will be obtained.
Now let's directly look at how a neodymium magnet is made. Unlike ferromagnetic products, the metal here is not melted, but sintered from a powder mixture placed in an inert or vacuum environment.
Then the resulting magnetoplast is pressed while simultaneously exposing it to an electromagnetic field of a certain intensity. As you can see, even at the initial stage of production, it is noticeable that the question of how to make neodymium magnets at home sounds inappropriate.
The operations and equipment used are too complex. Creating such conditions at home is hardly possible.
After the workpieces are removed from the molds, they are subjected to mechanical processing - they are carefully polished, then they are fired to improve the coercive force of the products.
Finally, we come to the last steps, which will help to finally answer the question of how neodymium magnets are made. The sintered NdFeB alloy is again machine-finished using a special tool. During operation, a cooling lubricant is used to prevent overheating or ignition of the powder.
A protective coating is applied to the magnets. This is due, firstly, to the fact that sintered metals are quite fragile and need to be strengthened, and, secondly, the metal will be protected from corrosion processes and other environmental influences.
So manufacturers worry in advance about how to make a neodymium magnet stronger and more durable. The coating can be copper, nickel, zinc. In the last phase of the production process, magnetization is applied through a strong magnetic field.
Then they are sent to the warehouse, and from there to customers.
So, after we examined the production process in more or less detail, it became clear that we probably shouldn’t seriously ask the question “how to make a neodymium magnet at home.” After all, this requires not only certain knowledge, but many complex units.
How to completely demagnetize a neodymium magnet
Neodymium magnets are very popular in modern industry and in solving a number of everyday problems. If the buyer (for example) chose strong magnets for delivery in St. Petersburg, but violated the storage or transportation conditions, as a result of which they stuck together, it may be necessary to carry out a demagnetization procedure. The same action may be necessary in other cases when it is necessary for the product to lose its qualities.
The process can be carried out in various ways, including using factory equipment, and it is necessary to decide how to demagnetize a neodymium magnet taking into account your capabilities.
Methods for demagnetizing a magnet
Loss of the ability to attract metal objects can occur both naturally and during a number of actions. Subject to the rules of operation and storage, the qualities of neodymium elements are maintained for 100 years or more, and ferrite analogues continue to attract metal for 8-10 years. Degaussing neodymiums naturally is not practical if the procedure is to be performed on a new item.
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Product heating
This method is used both in industrial and domestic conditions: if the magnet is made of a standard alloy of neodymium with boron and iron, it will lose its properties when placed in water boiling at 80 degrees Celsius or in case of contact with a surface heated to the specified temperature.
If we are talking about a product with increased resistance to thermal shocks, it is unlikely that it will be possible to perform the procedure at home: the demagnetization temperature of neodymium magnets with such properties is 200 degrees Celsius.
To carry out the procedure in such cases, special industrial equipment is used.
Mechanical Actions
Neodymium can lose its qualities as a result of a strong directed impact, for example, an impact: this material has a powder structure that is destroyed when dropped from a height or when exposed to impact equipment. In addition, demagnetization can occur accidentally during the process of drilling or cutting a magnet: this is due to excessive mechanical pressure or an increase in the temperature of the product without forced cooling.
Treatment with external magnetic influence
Most often, if it is possible to use industrial equipment of increased power, another magnet is used, which allows the formation of a field with an induction force of about 4 Tesla. A neodymium magnet is demagnetized in a matter of seconds, so this method, despite its technological complexity, is characterized by the fastest possible result.
How to magnetize demagnetized neodymium
If the demagnetization of an element occurs accidentally, and it is necessary to return the product to its properties, it is impossible to do this at home. Restoring a neodymium magnet requires the use of a product that can create a very powerful field, and this requires the use of professional equipment used to create such items.
Usually, if you need to return the magnetization properties for a specific element, you contact a factory that specializes in the production of such products.
Is there anything I can do to make the magnet stronger?
If neodymium used for household purposes has become demagnetized, often a more appropriate solution would be to purchase a new element. The cost of magnetization work varies depending on the required properties and pricing policy of a particular production.
Application of neodymium magnet
These products are available in various shapes and sizes and are used for the following tasks:
- Creating a clamping effect, fixing metal elements to each other. Using neodymium magnets, you can attach an antenna, license plate, plate, other metal part, device or entire mechanism.
- Filtration of oil systems in cars and other equipment: neodymium magnets allow you to easily and quickly remove metal shavings.
- Creation of magnetic locks and fasteners used in industrial sectors and household purposes.
- Search work related to the search for metal objects (search for treasures, historical values, weapons, mine clearance work, etc.).
- Restoring other magnetic elements: using a neodymium element, you can create a magnetic field that will return the product to its ability to attract metal.
- Deleting information recorded on floppy disks, disks, flash drives and other electronic media for security purposes.
- Creation of devices for universal use (hangers, stirring devices, compasses, etc.).
- Construction of current generators that can be used as experimental models or devices suitable for domestic use.
- Making jewelry: Neodymium can come in different shapes and sizes, and beads made from this material are often given a chrome finish and can be painted in different colors.
- Treatment of water using magnetic influence, as a result of which the formation of scale is reduced, and the liquid itself acquires an improved taste and smell.
- Fuel conditioning, which allows you to reduce fuel consumption for cars and motorcycles.
- Sorting small metal items that need to be removed from a variety of non-metal items.
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Conclusion
Neodymium magnets are products that are widely used in commercial, industrial and household applications, they are characterized by high load capacity, excellent attractive properties and durability.
Before demagnetizing neodymium magnets, it is important to make sure that you have the necessary equipment: this requires either an industrial installation or a device for heating to at least 80 degrees.
Magnetizing products that have lost their quality is rarely advisable, but if necessary, you can order the procedure by contacting the manufacturer.
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Source: https://magnetline.ru/metally-i-splavy/pochemu-magnity-razmagnichivayutsya.html
Why putting a magnet on a meter is a bad idea
To reduce water and electricity bills, some people put powerful magnets on their meters. Under the influence of a magnetic field, even during the consumption of water and light, the device does not rotate.
But a magnet is not an innocent way to save money. If a person uses water and electricity, but does not pay for them, he steals, that is, he commits an administrative offense. In the laws, this is called theft and is punishable by a fine, temporary arrest or community service.
Inspectors will probably know about the magnet
It seems that if you install a magnet only occasionally and pay a little on the bills, then no one will know about the violation. But inspectors have several ways to detect theft:
- See the magnet. Usually they try not to let the inspectors in or quickly remove the magnet before opening the doors. But it may happen that the person who placed it will not be at home, the door will be opened by a child or a grandmother who has come to stay, or the residents will simply forget about the magnet. Then the inspector will take a photo of the violation and draw up a report, and then you will be issued a fine.
- Check the indicator. Modern water and light meters have special indicators, or magnetic field sensors. It is enough to bring a powerful magnet to the meter once - and the indicator will change color forever. And some of the most modern devices can even send a message to the dispatcher, so they will instantly know about the magnet.
- Measure the magnetic field. If a magnet has recently been placed on the meter, the magnetic field around it will be abnormally large. It can be measured using a special device - a Teslameter. And if the indicator can sometimes somehow be fooled, then the Teslameter cannot be fooled: it will clearly indicate that there was a magnet on the meter.
The Teslameter is expensive and is still rarely used, but gradually this method is becoming more and more popular. You can especially often find inspectors with teslameters in Moscow and St. Petersburg.
To record a violation and draw up a report, inspectors must come to the meter in person. To do this, management companies (MCs) arrange scheduled inspections every 1–2 years. Theoretically, you can adapt to them and use the magnet only immediately after the inspectors’ visit in order to save at least a little.
But if according to the general building meter the resource consumption is the same, but according to the sum of the apartment meters it is significantly less, this indicates theft on the part of the residents. In this case, the management company can arrange an unscheduled inspection and detect the magnet.
You will be punished for installing a magnet
Most often, on the basis of Government Resolution No. 354, they are required to pay the cost of resources tenfold. The cost is calculated according to average standards and multiplied by the time that has passed since the last inspection, but by a maximum of 3 months.
That is, if you install a magnet and it is discovered in six months, you will be forced to pay 10 times more than you would pay according to the standards for three months. Standards, by the way, are often too high.
Usually people spend less than the average per month, so the overpayment will be large.
This fine is not related to theft - it only relates to violation of the meter. If the Criminal Code decides to sue, the violator faces the following penalties:
- A fine of 10–15 thousand rubles for the unauthorized use of electrical, thermal energy, oil or gas, according to the Administrative Code.
- A fine of five times the value of the stolen property for petty theft up to 1 thousand rubles, according to the Administrative Code.
- A fine for petty theft is from 1 to 2.5 thousand rubles in the amount of five times the value of the stolen property, or arrest for 10–15 days, or up to 120 hours of community service.
Theoretically, when more than 2.5 thousand rubles are stolen, the crime is no longer considered administrative, but criminal. He faces a fine of up to 300 thousand rubles or imprisonment for 1–2 years. But in fact, such punishments are not imposed in the Russian Federation for magnets on meters.
You can save money without a magnet
To save money, you don't need to install a magnet. There are several legal ways to pay much less for electricity and water:
- Use LED lamps. They consume 8–10 times less electricity than conventional ones.
- Turn off the water when you are not using it. This is useful to do even in small things, such as while brushing your teeth or in the shower while you lather up.
- Always turn off the lights when leaving a room. You can install motion sensors so that the lights turn on and off automatically.
- Install aerators on taps. They break the stream into small droplets, which creates greater pressure but reduces water consumption.
- Use a washing machine and dishwasher. They use less water than hand washing or washing, and they also use cheaper cold water rather than hot water. Electricity consumption increases, but the final payment decreases.
- Fix all leaks in a timely manner.
- If the tank has one flush mode, place a bottle filled with water in it. This will slightly reduce the volume of the tank. There will still be enough water to rinse, but the consumption will decrease.
- Install a tank with two flush modes to waste less water.
- If cold water flows for a long time before hot water, you can drain it into a bucket. Then the water can be used for flushing, watering plants or other purposes.
Reasonable consumption of resources will help you save money even without magnets, so you don’t have to fear inspections and fines.
Source: https://Lifehacker.ru/magnit-na-schyotchik/
Why does a magnet attract or everything about magnetic fields
Why does a magnet attract or everything about magnetic fields
Magnets, like the toys stuck to your refrigerator at home or the horseshoes you were shown in school, have several unusual features. First of all, magnets are attracted to iron and steel objects, such as the door of a refrigerator. In addition, they have poles. Bring two magnets closer to each other. The south pole of one magnet will be attracted to the north pole of the other.
The north pole of one magnet repels the north pole of the other. The magnetic field is generated by electric current, that is, by moving electrons. Electrons moving around an atomic nucleus carry a negative charge. The directed movement of charges from one place to another is called electric current. An electric current creates a magnetic field around itself.
This field, with its lines of force, like a loop, covers the path of electric current, like an arch that stands over the road. For example, when a table lamp is turned on and a current flows through the copper wires, that is, the electrons in the wire jump from atom to atom and a weak magnetic field is created around the wire.
In high-voltage transmission lines, the current is much stronger than in a table lamp, so a very strong magnetic field is formed around the wires of such lines. Thus, electricity and magnetism are two sides of the same coin - electromagnetism.
The movement of electrons within each atom creates a tiny magnetic field around it. An electron moving in orbit forms a vortex-like magnetic field. But most of the magnetic field is created not by the movement of the electron in orbit around the nucleus, but by the movement of the atom around its axis, the so-called spin of the electron. Spin characterizes the rotation of an electron around an axis, like the movement of a planet around its axis.
In most materials, such as plastics, the magnetic fields of individual atoms are randomly oriented and cancel each other out. But in materials like iron, the atoms can be oriented so that their magnetic fields add up, so a piece of steel becomes magnetized. Atoms in materials are connected in groups called magnetic domains. The magnetic fields of one individual domain are oriented in one direction.
That is, each domain is a small magnet. Different domains are oriented in a wide variety of directions, that is, randomly, and cancel each other's magnetic fields. Therefore, a steel strip is not a magnet. But if you manage to orient the domains in one direction so that the forces of the magnetic fields combine, then beware! The steel strip will become a powerful magnet and will attract any iron object from a nail to a refrigerator.
Magnetic iron ore mineral is a natural magnet. But still, most magnets are made artificially. What force can force atoms to line up to form one large domain? Place the steel strip in a strong magnetic field. Gradually, one by one, all domains will turn in the direction of the applied magnetic field.
As the domains rotate, they will draw other atoms into this movement, increasing in size, literally swelling. Then the identically oriented domains will connect, and lo and behold, the steel strip has turned into a magnet. You can demonstrate this to your comrades using an ordinary steel nail. Place the nail in the magnetic field of a large neodymium magnet.
Hold it there for a few minutes until the nail domains line up in the desired direction. Once this happens, the nail will briefly become a magnet. With its help you can even pick up fallen pins from the floor.
Why doesn't a magnet attract everything?
In fact, the interaction of a magnet with substances has many more options than just “attracts” or “does not attract.” Iron, nickel, and some alloys are metals that, due to their specific structure, are very strongly attracted by a magnet.
The vast majority of other metals, as well as other substances, also interact with magnetic fields - they are attracted or repelled by magnets, but only thousands and millions of times weaker.
Therefore, in order to notice the attraction of such substances to a magnet, you need to use an extremely strong magnetic field, which you cannot get at home.
But since all substances are attracted to a magnet, the original question can be reformulated as follows: “Why then is iron so strongly attracted by a magnet that manifestations of this are easy to notice in everyday life?” The answer is: it is determined by the structure and bonding of iron atoms. Any substance is composed of atoms connected to each other by their outer electron shells.
It is the electrons of the outer shells that are sensitive to the magnetic field; they determine the magnetism of materials. In most substances, the electrons of neighboring atoms feel the magnetic field “at random” - some repel, others attract, and some generally try to turn the object around.
Therefore, if you take a large piece of a substance, then its average force of interaction with a magnet will be very small.
Iron and metals similar to it have a special feature - the connection between neighboring atoms is such that they sense the magnetic field in a coordinated manner. If a few atoms are tuned to be attracted to a magnet, they will cause all neighboring atoms to do the same. As a result, in a piece of iron all the atoms “want to attract” or “want to repel” at once, and because of this, a very large force of interaction with the magnet is obtained.
A magnet is a body that has its own magnetic field. In a magnetic field, there is some effect on external objects that are nearby, the most obvious being the ability of a magnet to attract metal.
The magnet and its properties were known to both the ancient Greeks and the Chinese. They noticed a strange phenomenon: small pieces of iron were attracted to some natural stones.
This phenomenon was first called divine and used in rituals, but with the development of natural science it became obvious that the properties were of a completely earthly nature, which was first explained by the physicist from Copenhagen Hans Christian Oersted.
He discovered in 1820 a certain connection between the electric discharge of current and a magnet, which gave rise to the doctrine of electric current and magnetic attraction.
Natural science research
Oersted, conducting experiments with a magnetic needle and a conductor, noticed the following feature: a discharge of energy directed towards the needle instantly acted on it, and it began to deviate.
The arrow always deviated, no matter from which side he approached.
A physicist from France, Dominique François Arago, began repeated experiments with a magnet, using as a basis a glass tube rewound with a metal thread, and he installed an iron rod in the middle of this object.
With the help of electricity, the iron inside began to be sharply magnetized, because of this various keys began to stick, but as soon as the discharge was turned off, the keys immediately fell to the floor.
Based on what was happening, a physicist from France, Andre Ampere, developed an accurate description of everything that happened in this experiment.
When a magnet attracts metal objects to itself, it seems like magic, but in reality the “magical” properties of magnets are associated only with the special organization of their electronic structure. Because an electron orbiting an atom creates a magnetic field, all atoms are small magnets; however, in most substances the disordered magnetic effects of atoms cancel each other out.
The situation is different in magnets, the atomic magnetic fields of which are arranged in ordered regions called domains. Each such region has a north and south pole. The direction and intensity of the magnetic field is characterized by the so-called lines of force (shown in green in the figure), which leave the north pole of the magnet and enter the south.
The denser the lines of force, the more concentrated the magnetism. The north pole of one magnet attracts the south pole of another, while two like poles repel each other. Magnets attract only certain metals, mainly iron, nickel and cobalt, called ferromagnets.
Although ferromagnetic materials are not natural magnets, their atoms rearrange themselves in the presence of a magnet in such a way that the ferromagnetic bodies develop magnetic poles.
Magnetic chain
Touching the end of a magnet to metal paper clips creates a north and south pole for each paper clip. These poles are oriented in the same direction as the magnet. Each paper clip became a magnet.
Countless little magnets
Some metals have a crystalline structure made up of atoms grouped into magnetic domains. The magnetic poles of the domains usually have different directions (red arrows) and do not have a net magnetic effect.
Formation of a permanent magnet
Typically, iron's magnetic domains are randomly oriented (pink arrows), and the metal's natural magnetism does not appear. If you bring a magnet (pink bar) closer to the iron, the magnetic domains of the iron begin to line up along the magnetic field (green lines). Most of the magnetic domains of iron quickly align along the magnetic field lines. As a result, the iron itself becomes a permanent magnet.
Magnetic effect
Today it is obvious that the matter is not in miracles, but in a more than unique characteristic of the internal structure of the electronic circuits that form magnets. An electron that constantly rotates around an atom forms the same magnetic field.
Microatoms have a magnetic effect and are in complete equilibrium, but magnets, with their attraction, influence some types of metals, such as iron, nickel, cobalt.
These metals are also called ferromagnets. In close proximity to a magnet, atoms immediately begin to rearrange and form magnetic poles.
Atomic magnetic fields exist in an ordered system; they are also called domains. In this characteristic system there are two poles opposite to each other - north and south.
Application
The north pole of a magnet attracts the south pole, but two identical poles immediately repel each other.
Modern life without magnetic elements is impossible, because they are found in almost all technical devices, including computers, televisions, microphones, and much more. In medicine, magnets are widely used in examinations of internal organs and in magnetic therapy.
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The material uses photos and excerpts from:
https://information-technology.ru/sci-pop-articles/23-physics/231-pochemu-magnit-prityagivaet-zhelezo
https://kakprosto.ru/kak-821401-pochemu-magnit-prityagivaet-zhelezo
https://voprosy-kak-i-pochemu.ru/pochemu-magnit-prityagivaet-ili-vse-o-magnitnyx-polyax/
https://log-in.ru/articles/pochemu-magnit-ne-vse-prityagivaet/
Source: https://magnet-prof.ru/index.php/pochemu-magnit-prityagivaet-ili-vse-o-magnitnyih-polyah.html