Conditions for ferromagnetism in magnetic component processing

Ferromagnetism refers to the fact that the magnetic moments of adjacent atoms or ions in a substance are roughly aligned in the same direction in some regions due to their interaction. When the applied magnetic field strength increases, the combined magnetic moment of these regions is aligned. will increase to a certain limit. What are the conditions for the processing of ferromagnetism in magnetic components?

1. There should be an unfilled electron shell inside the atom;

2, and the ratio of Rab/r greater than 3 makes the exchange integral A positive. The former means that the intrinsic magnetic moment of the atom is not zero; the latter means that there must be a certain crystal structure.

According to the process and theory of spontaneous magnetization, many ferromagnetic properties can be explained. For example, the effect of temperature on ferromagnetism. When the temperature increases, the atomic spacing increases, which reduces the exchange effect, and the regular orientation of the atomic magnetic moment is continuously destroyed by thermal motion, so the spontaneous magnetization Ms decreases.

Until the temperature is higher than the Curie point, the regular orientation of the atomic magnetic moment is completely destroyed, the spontaneous magnetic moment does not exist, and the material changes from ferromagnetic to paramagnetic. Also, magnetocrystalline anisotropy, magnetostriction, etc. can be explained.