Magnetic material, commonly referred to as a magnetic material refers to a ferromagnetic substance, is old and uses a very wide range of functional materials, and magnetic materials as early as 3,000 years ago by people understanding and applications, such as in ancient China using natural magnet compass. Modern magnetic materials have been widely used in our lives, such as permanent magnet material is used as a motor, is applied to the transformer core material, as magneto-optical memory usage, computer floppy disks and other magnetic recording. Great bit of information on said magnetic material and information technology, automation, mechatronics, national defense, national economic aspects are closely related. And generally it believed that a magnetic material is defined by excessive elemental iron, cobalt, nickel and alloys capable of directly or indirectly generate a magnetic substance. After pressing the magnetic magnetization demagnetization of difficulty can be divided into soft magnetic materials and hard magnetic materials. Easily removed after the magnetization of the magnetic substance called soft magnetic material, it is not easy to magnetic substance called hard magnetic materials. In general, the soft magnetic remanence smaller, larger hard magnetic remanence.