Magnetic materials are widely used in electroacoustics, telecommunications, electricity meters, motors, memory elements, microwave elements, etc. Our bodies and the earth we live on, as far away as the distant universe, all the materials that make up them have magnetism. We live in a magnetic world and the application of magnetism is ubiquitous. Different magnetic materials
have different applications.
Magnetic materials mainly refer to materials composed of transition elements such as iron, cobalt, nickel and their alloys that can directly or indirectly produce magnetism. Modern magnetic materials have been widely used in our life, for example, permanent magnetic materials are used as motors, iron core materials used in transformers, magneto-optical disks used as memories, magnetic recording floppy disks for computers, etc. It can be said that magnetic materials are closely related to all aspects of informatization, automation, mechatronics, national defense and national economy. It is generally believed that magnetic materials refer to substances that can directly or indirectly generate magnetism from transition elements such as iron, cobalt, nickel and their alloys. Magnetic materials are mainly from natural magnetite and artificial alloys containing cobalt and iron. Now the artificially synthesized iron-cobalt alloys containing rare earth elements are full of extremely strong magnetism.
In terms of application function, magnetic materials can be divided into permanent magnetic materials, soft magnetic materials, magnetic recording-moment magnetic materials, gyromagnetic materials, etc. Soft magnetic materials, permanent magnetic materials and magnetic recording-moment magnetic materials include both metal materials and ferrite materials. However, gyromagnetic materials and high-frequency soft magnetic materials only consist of ferrite materials. Metal will produce huge eddy current effect at high frequency and microwave frequency, making metal magnetic materials fail to be used. This problem will be resolved by ferrite containing high resistivity, which will be widely used.