Permanent magnet materials, also known as "hard magnetic materials", refer to materials that can maintain constant magnetism once magnetized. In practice, the permanent magnet material works in the second quadrant of the hysteresis loop after deep magnetic saturation and magnetization. Commonly used permanent magnet materials are divided into rare earth permanent magnet, ferrite permanent magnet, metal permanent magnet, composite permanent magnet, etc. The magnets we mention generally refer to permanent magnet.
