Explanation

The theory uses quantum theory to explain the magnetize mechanism of ferromagnetic materials from a microscopic perspective. The so-called magnetic domain refer to small magnetize regions with different directions generated by iron materials in the process of spontaneous magnetize in order to reduce the magnetostatic energy. Each region contains a large number of atoms. The magnetic moment of these atoms are orderly arranged like small magnets, but the magnetic moment of an atom between adjacent different regions are arranged in different directions, as shown in the overview diagram. The interface between each magnetic domain is called the magnetic domain wall. Macroscopic objects generally have many magnetic domain. In this way, the magnetic moment directions of magnetic domain are different, and the results cancel each other. The vector sum is zero, and the magnetic moment of the whole object is zero, so it cannot attract other magnetic materials. That is to say, magnetic materials do not show external magnetism under normal conditions. Only when the magnetic materials is magnetize can it show its magnetism externally.

Classification