Magnetic materials are widely used materials in production, life, and national defense science and technology. Such as the manufacture of various motors and transformers in power technology, various magnetic components and microwave tubes in electronic technology, filters and intensifiers in communication technology, magnetic mines, electromagnetic guns, various household appliances in national defense technology, etc. . In addition, magnetic materials have also been widely used in geological and mineral exploration, ocean exploration, and new technologies in information, energy, biology, and space. Magnetic materials have a wide range of uses. Mainly use its various magnetic properties and special effects to make components or devices; used to store, transmit and convert electromagnetic energy and information, or generate a certain intensity and distribution of magnetic fields in a specific space; sometimes directly in the natural form of the material Use (such as magnetic liquid). Magnetic materials play an important role in the field of electronic technology and other fields of science and technology.