2021-06-15

Explain the magnetization process of ferromagnetic materials with magnetic domain theory

By yqqlm yqqlm

Answer:In ferromagnets, there is a very strong exchange coupling between electrons in adjacent iron atoms. This interaction promotes electrons in adjacent atomsMagnetic moments are arranged in parallel to form a small area where the spontaneous magnetization reaches saturation. These small areas of spontaneous magnetization are called Magnetic domain.

The magnetization process of the magnetic domain is as follows:

1→When no external magnetic field is applied, the magnetic moment of the magnetic domain is chaotic. It does not show macroscopic magnetism to the outside.

2→Under the action of a small magnetic field, the magnetic domain whose direction of the magnetic moment is the same or close to the direction of the applied magnetic field increases in volume, and the direction of the magnetic moment and the direction of the applied magnetic field are the same as that of the applied magnetic field. The volume of the magnetic domain with the opposite direction of the magnetic field decreases, and the domain wall is displaced.

3→When the external magnetic field is increased, the magnetic moment rotation domain wall continues to shift, and finally only the magnetic domains that are closer to the external magnetic field are left.

4→Continue to increase the external magnetic field, and the direction of the magnetic moment will rotate, which is close to the direction of the external magnetic field.

5→When the applied magnetic field increases to a certain value, the magnetic moments of all magnetic domains are arranged in order along the direction of the applied magnetic field, reaching magnetization saturation, which is equivalent to a tiny Magnets or magnetic dipoles produce N-level and S-levels, which exhibit magnetism in a macroscopic view.