The brief introduction of the magnetic material

　　Magnetic material is ancient functional materials with the very extensive use, and the magnetic properties of matter in early 3000 had been recognized and used, for example in ancient China, use a natural magnet as compass.

　　Modern magnetic materials have been widely used in our life, for example, the permanent magnets' material is used as a motor, used in transformer's core material, as the memory usage of a magnetic disc, magnetic recording disk and other computer. It can be said that, magnetic materials are closely related to informatization, automation, mechanical and electrical integration, defense, every aspect of national economy. Usually think that, magnetic material is defined by the excessive elements of iron, cobalt, nickel and its alloy, the magnetic material that can directly or indirectly produce magnetic.

　　Experimental results show that, no matter in the external magnetic field can, more or less, be magnetized, only the magnetized degree is different. According to the material's characteristic, showed in the external magnetic field, material can be divided into five categories: paramagnetic substances, anti-magnetic material, ferromagnetic material, sub-magnetic substance, anti-magnetic material.