solenoidsAny electron in a molecule or Atom that makes up a substance, I participates in two movements at the same time: the orbital setting around the atomic nucleus and its own spin motion, and the breaking effect of these two motion surfaces. If the molecule is considered as a whole, the magnetic effect of each item can be represented by the molecular magnetic moment M generated by the equivalent topic current(the so-called molecular current). Now let the material be under the action of the external magnetic field B. At this time, any electron in the molecule or Atom will be used by the power of Loren, and it will produce a rotational motion in which the axis coincides with the direction of the external magnetic field, that is, the precession of the electrons. Similarly, the electron is also equivalent to a coil current, which produces the direction of the additional magnetic moment SM. Always with external magnetic field B. The opposite direction 1-1).
Different substances have different atomic structures, so the size of their molecular magnetic moments and additional road moments and their interaction with each other are also different. In this way, the magnetic properties of different "substances" under the action of external magnetic fields are also very different.
In general, the strength of material magnetism is expressed as the strength of the breakdown polarization. It is equal to the vector sum of each unit's magnetic moment per unit volume and is proportional to the macroscopic magnetic field strength inside the material.
Considering that "and H are discontinuous in some cases, and the magnetic induction intensity B is always continuous, the concept of magnetic induction intensity is more often used in engineering.
For recursive magnetic substances, the molecular weight moments of each molecule are equal. Only under the action of the external magnetic field, there is an additional sister that is opposite to the direction of the external magnetic field. Therefore, X & lt of this type of substance; 0, Np & lt; 1. For developmental substances. Although each of its molecules can produce a certain molecular moment. West and much larger than the additional moment but carrying any unit volume theory, because the arrangement of the magnetic moments of each molecule is disorganized, their vectors are military, so this kind of material is not fundamentally magnetic. If the magnetic field is added to the same magnetic material, the molecules produced by each molecule will be arranged under the action of the external magnetic field, and the orientation of the molecular moment will be compared with the direction of the external magnetic field, so it can enhance the breaking field. The effect. Therefore, * & GT of paramagnetic material; 0, face U & GT; 1. The above effects of diamagnetic and plasmic magnetic substances are customarily referred to as inverse magnetic effects and paramagnetic effects. *
Transmagnetic substances include ammonia and emotional gases, many organic compounds, Stone stars, and certain metals(such as chains, surprises, Buddhas, copper, silver, gold, Mercury, etc.). The inverse magnetic effect is actually very weak, and even if it is the most diamagnetic fault, its magnetic conductivity is almost the same as 1(U 0.9983). There are many gases, metals, and their salts(such as false, platinum, iron, estimated, inlaid, alkaline earth, and rare earth metals, etc.) that belong to plasmic magnetic substances. Although the permeability of paramagnetic materials is greater than 1, it is not much different from 1.
The strong magnetic material is characterized by its particularly strong paramagnetic effect, so its conductivity is much greater than 1, or even up to hundreds of thousands or even millions. Among the strong magnetic substances are: iron, cobalt, alloying and their alloys, gadolinium, and certain oxides of iron and nickel. Steel, manganese and alloy museum, etc.. Since strong magnetic substances are mostly used for iron and its oxides and its alloys, it is customary to refer to strong magnetic substances as ferromagnetic substances.
Why is the paramagnetic effect of ferromagnetic material particularly strong? This is difficult to explain by the magnetic effect of molecular currents. For example. Iron atoms have the same magnetic moment as nameplate atoms, but the former is a typical strong magnetic material, while the latter is a ductile material. Steel, manganese, and Ji are not strong magnetic substances, but their alloys are iron. Tong material. These facts all illustrate the problem that the ferromagnetism presented by ferromagnetic materials is not determined by the nature of their molecules or atoms, but by their solid structure. In fact, all ferromagnetic materials are not side-by-side crystalline circular bodies.
It turns out that there are many small areas in ferromagnetic materials that spontaneously magnetize to the state of Guhe. In the absence of an external magnetic field, although each of these spontaneously magnetized regional domains has a certain orientation, from a macroscopic point of view, they are not shown externally because they are arranged irregularly. Once these domains are under the action of an external magnetic field. They turn completely and are arranged very neatly, making ferromagnetic materials strongly magnetized until they are saturated. If very fine iron powder is sprinkled on the surface of the single product of the iron breaking material that has been removed after being polished. *
It should be pointed out that the magnetization of a single product of ferromagnetic materials is anisotropic. In the monomorphic view of iron. It is easy to magnetize along the plane(100 directions), magnetization along the diagonal(110 directions) of the plane is the only one, and the sliding three-dimensional diagonal(111 directions) is difficult to report(Figure 1-3). The magnetization of the white hair of the magnetic domain is always carried out along one side of the single crystal. Different ferromagnetic materials have different single product structures, so the direction of magnetization is also different. This magnetic Anisotropy is also a characteristic of iron materials. It is the interaction of the feelings of the beings between the Shaoyuanzi.
For any ferromagnetic material, each has its own unique fixed temperature. If the temperature of the iron material changes this degree, the quantity domain in Laer will disappear, and the surface iron material will become a functional magnetic material.