Soft Ferrites

Soft Magnetic Material

Material can be divided into ferromagnetism, ferrimagnetism, paramagnetism, diamagnetism, and anti-ferromagnetism based on their magnetism behavior and bulk magnetic susceptibility. Materials with ferromagnetism or ferrimagnetism are collectively referred to as magnetic materials. Magnetic materials can be further subdivided into soft magnetic materials, permanent magnetic materials, gyromagnetic materials, rectangular hysteresis materials, and piezomagnetic materials. Soft magnetic materials which otherwise known as soft magnet, is a corresponding concept against hard magnet. Those unfamiliar with magnetism are easy to misinterpret “soft” and “hard” from literally or material hardness, then mistake soft magnet for rubber magnet. In reality, the words “hard” and “soft” here is not mechanical but magnetism. Soft magnetic material is a type of magnetic material which able to quickly respond to change of the external magnetic field and obtain high magnetic flux density under low loss. Soft magnet possesses low coercivity and high permeability, therefore, it can be easily magnetized and demagnetized. Soft magnetic material is widely used in magnetic cores of transformers, inductors, motors, and generators. 

Soft Ferrites

Soft ferrites refer in particular to the ferrite material which can be easily magnetized and demagnetized by the weak magnetic field. As a semiconductor, the greatest advantage of soft ferrites is definitely high electrical resistivity in comparison with traditional metal soft magnetic material, therefore, soft ferrite coresown excellent high-frequency characteristics. In the meanwhile, soft ferrites possess low cost. The shortcomings of soft ferrite material include low saturation magnetic flux density and the Curie temperature. Besides, temperature stability of magnetic properties is generally inferior to metal soft magnetic material. But even so, soft ferrites still have an unshakable status in high-frequency applications in the future for a long period. Chemical composition and manufacturing technology of soft ferrite material have been continuously developed and improved since 1930s, then emerged MnZn ferrite, NiZn ferrite, MgZn ferrite, LiZn ferrite, and hexagonal ferrite. 

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