In the absence of an applied magnetic field, the exchange of electrons between adjacent atoms in the magnetic domain or other interactions. After the magnetic moments of their forces overcome the influence of thermal motion, the powerful magnets are in a partially canceled orderly arrangement, so that there is also a phenomenon of the combined magnetic moment [1]. When an external magnetic field is applied, its magnetization varies with the external magnetic field similar to that of a ferromagnetic substance. Ferrimagnetic and antiferromagnetic have the same physical nature, except that the antiparallel spin magnetic moments in the ferrimagnetic magnets vary in size, so there is a partial offset of the spontaneous magnetic moment, similar to ferromagnetics. Ferrites are mostly ferrite magnets.
The diamagnetism is that the electron magnetic moments in the atoms of some substances cancel each other out, and the magnetic moment is zero. However, when the magnetic steel is subjected to an external magnetic field, the movement of the electron orbit changes, and a small magnetic moment is generated in the opposite direction to the applied magnetic field. A strong magnet indicates that the magnetic susceptibility of a substance becomes a small negative number (amount). The magnetic susceptibility is the ratio of the combined magnetic moment (called magnetization) of a substance under the action of an external magnetic field to the strength of the magnetic field, and the sign is κ. Generally, the magnetic susceptibility of a diamagnetic material is about one millionth (-10-6).