Ferrite Magnet is sintered from iron oxide and other ingredients. Generally can be divided into three types of permanent ferrite, soft ferrite, and spin ferrite.
Permanent ferrite is also called ferrite magnet. It is the small black magnet we usually see. Its constituent raw materials are mainly iron oxide, barium carbonate, or strontium carbonate. After magnetization, the intensity of the residual magnetic field is very high, and the residual magnetic field can be maintained for a long time. Usually used as a permanent magnet material. Example: speaker magnet.
Soft ferrite is made of ferric oxide and one or several other metal oxides (for example nickel oxide, zinc oxide, manganese oxide, magnesium oxide, barium oxide, strontium oxide, etc.) The reason why it is called soft magnetic is that when the magnetizing magnetic field disappears, the residual magnetic field is very small or almost non-existent. It is usually used as a choke coil or a magnetic core of an intermediate frequency transformer. This is completely different from a permanent ferrite.
A gyroferrite is a ferrite material with gyromagnetic properties. The gyromagnetic of magnetic materials refers to the phenomenon that the plane of plane polarization of electromagnetic waves propagates in a certain direction inside the material under the action of two mutually perpendicular DC and electromagnetic magnetic fields. [1]. Rotary ferrites have been widely used in the field of microwave communications. According to the crystal type, spin ferrite can be divided into spinel type, garnet type, and magnetite type (hexagonal type) ferrite.
Ferrites are relatively inexpensive and cost-effective.

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