What is the microscopic principle of a magnet? Chemistry .

Analysis and answer: Matter is mostly composed of molecules, molecules are composed of atoms, and atoms are again.

by the nucleus. and electrons. Inside the atom, the electrons rotate incessantly and revolve around the nucleus. Both of these motions of electrons produce magnetism. But.

In most matter, the direction of electron movement is varied and disorganized, and the magnetic effects cancel each other out. Therefore, most substances under normal conditions do not.

It is magnetic, and there is no magnetic force on the outside. Iron, cobalt, nickel or ferrite.

and other ferromagnetic classes. Matter is different in that the spin of electrons inside it can be spontaneous in a small area.

Arranged together, a spontaneous magnetization zone is formed, and this spontaneous magnetization zone is called a magnetic domain.

After the ferromagnetic material is magnetized, the internal magnetic domains are neat and directionally consistent.

Arrange them so that the magnetism is strengthened, and the magnet is formed. The process of magnet iron absorption.

It's against the pieces of iron.

The magnetization process, the magnetized iron block and the magnet have different polarities.

The iron is firmly "glued" to the magnet.

We say that magnets are magnetic, and magnets have magnetic force.

Permanent magnets can be assumed to be composed of many tiny magnetic domains, each of which has the same direction of magnetic moment. Magnetic moments, on the other hand, are equivalent to an infinite number of toroidal currents in the molecular current hypothesis. In a macroscopic permanent magnet, the two poles correspond to the positive and negative directions of the magnetic moment, which corresponds to the left-hand and right-hand spiral directions of the toroidal current.

When the same poles meet, it is equivalent to two wires with the same current in the same direction parallel, and the Coulomb force causes them to repel each other. In the same way, opposites attract.

The various magnetic properties of materials are the result of the coupling of these three magnetic properties with each other and their interaction with the environment. Diamagnetism (the magnetization of the inside in the opposite direction when an external magnetic field is applied).

**Additional magnetic moment generated when the magnetic field line passes through the spin magnetic moment, opposite to the direction of the external magnetic field. Diamagnetism is ubiquitous and is present in any material, but it is very faint and may be masked by other properties. Paramagnetism (the magnetization of the same direction inside after the addition of an external magnetic field) can be understood as the orientation behavior of the atomic magnetic moment (the coupling of the electron magnetic moment with the orbital magnetic moment) under the action of the external field.

Originally, it was random and chaotic, and the magnetic moment was zero on average. After adding the external field, there is orientation, and the macroscopic paramagnetic moment is generated, which is relatively weak. Ferromagnetism (no need to collapse the outer field to have magnetism, spontaneous magnetization)** is more complicated, which can be roughly understood as sometimes the parallel energy of the spins of adjacent electrons is lower, so that at low temperatures, it will spontaneously magnetize, resulting in ferromagnetism, which is a strong magnetism.

Antiferromagnetism (macroscopically manifested as no magnetism, but in fact the magnetism in two directions cancels each other out) is the opposite of ferromagnetism, the spin antiparallel energy of adjacent electrons is lower, and the two sublattice magnetism cancel each other out, weakly magnetic. Ferromagnetism (similar to ferromagnetism, but different in some physical laws) is roughly understood as two sets of antiparallel electron spins that do not completely cancel out, and the remaining spontaneous magnetization. Ferromagnetic.

Of course, these are only very general and non-rigorous generalizations, each magnetic property has other ** (such as Landau diamagnetism, van Vleck paramagnetism, Pauli paramagnetism, etc.), and the same magnetic properties are not the same in various materials ** (cruising electron model of transition metals, indirect exchange of metal oxides, rkky model of rare earth metals, etc.), even the same material will exhibit different magnetic properties under different environmental conditions (temperature, external magnetic field, pressure, etc.). For the time being, there are still some incomprehensible phenomena, or these traditional interpretations have their own limitations. The magnetic properties of materials have a wide range of applications, and the physical phenomena in them are also very rich and interesting.

I hope this superficial article is helpful in understanding.

As a physical field, magnetic field is a special substance that cannot be seen or touched, but exists objectively. It is the medium of magnetic interaction, a bit mysterious but a real impact on our lives. And the subject's confusion is our confusion about the causes of magnetism.

Quantum characteristics — spin-based. We need to elaborate on these two parts separately. The subject's "we learned in high school that magnetic fields are generated around changing electric fields" is the first origin, and the subject's next mention of "such as magnetism in amorphous materials, and some crystalline materials also do not have obvious magnetism" is not true, but it actually refers to the second origin.

The first reason we are most familiar with is that "moving charges produce magnetic fields". It comes from Faraday's law of electromagnetic induction.

Just memorize it. But if you have to ask why, because there are many masters in electromagnetism, I won't take the axe, roughly speaking: electric field and magnetic field are two sides of the electromagnetic tensor, and they are related to each other. When due to the reference system large lead.

different and make the observer.

When the relative velocity between the charge and the charge changes, the electromagnetic tensor may split into the electric and magnetic fields generated by the moving charge.

I think the multi-cavity leak is talking about the second origin: spin-based ferromagnetic matter.

magnetism. First of all, there is a point to clarify. Since spin is an essential property of some of the elementary particles that make up matter (e.g., electrons) (see Figure 2), all matter is theoretically "magnetic".

The difference is that different substances exhibit different types of magnetic properties (Figure 3). The term "magnet" refers to a "ferromagnetic substance" that provides magnetic energy (magnetic field) independently (when there is no external field), that is, a permanent magnet. That's what we're talking about.

I think you're trying to ask about the nature of electromagnetic fields, which is hard to understand. The following is the answer I have collected and collated, I hope it will be helpful for your understanding.

A field refers to the distribution of an object in space. The field is characterized by a spatial position function. In physics, it is often necessary to study the distribution and change law of a certain physical quantity in space.

If a physical quantity is a scalar quantity, then each point in space corresponds to a definite value of that physics, then this space is called a scalar field. Such as electric potential field, temperature field, etc. If the physical quantity is a vector quantity, then every point in the space has its magnitude and direction, then this space is called a vector field.

Such as electric field, velocity field, etc. The U-shaped magnet inductance line distribution field indicated by iron filings is a special substance that cannot be seen or touched, but it does exist. Such as gravitational fields, magnetic fields, and so on.

Einstein denied the existence of the ether in the special theory of relativity, but the establishment of the general theory of relativity reflects a clear change in Einstein's thinking. He pointed out that general relativity "is a field theory" and that "if constants are substituted for those functions that describe the ether of general relativity, without considering any of the reasons that determine the ether, then the ether of general relativity can become the Lorentz ether in the imagination."

Einstein even tried to unify the various fields into a flawless theory. The field is a basic form of physical existence. The main feature of this form is that the field is diffuse throughout the space.

The essence of the field is a kind of substance that cannot be seen, touched, or massless, but will have an impact on the objects that exist in it, and the specific explanation is very complicated, and it is a complete discipline "Field Theory".

The field is the two basic forms of the existence of matter that coincidentally coincide with the particles The state with the lowest energy of the field is called the ground state of this field, when a field is in the ground state, this field cannot release energy through the change of state and output any signal, so that it will not show direct physical effects, which is manifested as not seeing the existence of particle fields When the field is in the excited state, it is manifested as the appearance of corresponding particles, and the different excitation states of the field are manifested as the number of particles and the difference in the state of trembling

Therefore, it cannot be said that the field is composed of any substance, it is only a way of energy existence, and it can only be said that a certain field corresponds to a certain particle. For example, there is an electromagnetic field corresponding to a photon, an electron field corresponding to an electron, and a proton field corresponding to a proton. Therefore, the electric field and the magnetic field can be regarded as the same field, which is transmitted by photons.

There is a layered explanation that goes something like this:

1.Classical physics argues; The electric field is essentially the medium of electric field force propagation and is part of the electromagnetic field.

2.Quantum field theory holds that photons are particles that propagate electromagnetic interactions.

3.String theory holds that the known "basic" particles (including photons) are closed circles of very small strings, and that the differences between the various particles are only differences in the way and shape of the strings jitter. (presumably meaning that all particles are manifestations of different forms of vibration of strings, and fields are no exception), string theory is currently only a hypothesis.

To sum up, the electromagnetic field is a specific vibration of the string.

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