Determined by the characteristics of the magnet, if the atomic current is explained by the magnetic field generated by the current magnetization of other objects, the magnetic field generated by the object, the interaction between the electric field force.

Most of the material is composed of molecules, molecules are made of atoms, atoms and nuclei and electrons. Inside the atom, the electron keeps spinning and rotates around the nucleus. Both types of movement of electrons produce magnetism. However, in most materials, the direction of electron movement is different and disorganized, and the magnetic effects cancel each other out. Therefore, most substances do not show magnetism under normal conditions.

Iron, cobalt, nickel or ferrite and other ferromagnetic substances are different, its internal electronic spin can spontaneously arranged within a small area to form a spontaneous magnetization zone, this spontaneous magnetization zone called magnetic domain. Ferromagnetic material after magnetization, the internal magnetic domain neat, aligned in the same direction, so that the magnetic reinforcement to form a magnet. Magnet iron absorption process is the magnetization process of iron, magnetized iron and magnet attraction between the different polarities, the iron firmly with the magnet "stick" together.

Natural magnets are ferrosilicon and artificial magnets are usually steel. After the magnetization of steel will always retain the magnetic, the general refers to the natural permanent magnet is not just ferrite (ferroferric oxide), as well as iron-cobalt-nickel alloy, iron and other rare earth alloy permanent magnet materials such as aluminum Nickel cobalt, samarium cobalt, neodymium iron boron, these are also very common, very strong magnetic, these substances can be magnetic field constant magnetic field, and after magnetization itself is magnetic and does not disappear. The composition of the magnet is based on the magnetizability of the various metals, as the need arises. The magnet approaches (touches) the magnetic substance, which senses the opposite pole at one end and the pole at the other end.

Magnet classification

A, temporary (soft) magnet

a. Meaning: Magnetism is short and magnetism disappears when the magnet is removed.

b. Example: nails, wrought iron

B, permanent (hard) magnet

a. Significance: After magnetization, it can keep magnetism for a long time.

b. Example: nail

According to the above information is summarized as follows:

According to the principle of electromagnetic induction, a very strong current can produce a strong magnetic field. The ferromagnetic material is magnetized by a strong magnetic field. Since the magnetization characteristics of different materials are different, some materials are easy to magnetize and are not easily demagnetized (losing magnetism) Can retain the magnet for a long time. Magnetizing this material produces a magnet.

Use magnetizer to magnetize hard magnet.

According to the principle of electromagnetic induction, the current can produce a magnetic field, the use of strong magnetic field to magnetize hard magnetic materials are generally referred to as the magnetic material of the magnet, in fact, is several different things: the most common magnet, such as the general speaker magnet is iron Magnetizing magnet. They are used in steel mills hot-rolled from the surface of the billet rolled off the scale (flaky iron oxide), after the impurity, crushed and then add a small amount of other substances into the steel mold pressure molding , And then in the reducing furnace (through hydrogen) sintering, so that part of the oxide reduction ferrite, cooling, and then placed in the exciter magnetizing produced. More sophisticated than them is the magnet: Magnet is a real steel, with the exception of iron, the main high nickel content. It is generally medium frequency electric furnace smelting (only 100 kilograms per furnace), casting molding, because of the accuracy of some of the plane requirements, generally have to use grinder grinding. Then magnetize, become a product. This kind of magnet is used in all kinds of meters. More advanced magnetic materials, is NdFeB magnet. They are rare earth elements containing neodymium, iron and boron. Production is the method of carbide production: after milling - mixing - molding - sintering - finishing - from magnetization. The highest magnetic field strength of such magnetic materials, the best performance, the most expensive price. It is only used in the defense industry and precision equipment. The rotor in the electronic watch's stepper motor is. Ah, maglev train is definitely used for this kind of magnetic material.

Ferrite permanent magnet materials are: strontium - ferrite permanent magnet materials and barium - ferrite permanent magnet materials, there are isotropic and anisotropic points, the speaker magnet commonly used ferrite permanent magnetic materials ;

Metal permanent magnet materials are mainly Alnico permanent magnet materials and rare earth permanent magnet materials. Rare earth permanent magnet material is divided into: SmCo permanent magnet material and NdFeB permanent magnet material. Rare earth permanent magnet material is made by powder metallurgy process.

Magnetic strength? I did not find convincing information for now.