(1) Soft magnetic material: high magnetic permeability, easy to magnetize and demagnetize (large initial magnetic susceptibility). The saturation magnetic induction is large, the coercive (Hc) is small, the area of the hysteresis loop is narrow and long, and the loss is small (the HdB area is small). Including magnetic pure iron, silicon steel permalloy (Fe, Ni) ferrite, the most widely used soft magnetic material is iron silicon alloy (silicon steel sheet) and various soft ferrites.
Mainly used in magnetic antenna, inductor, transformer, magnetic head, earphone, relay, vibrator, TV deflection yoke, cable, delay line, sensor, microwave absorbing material, electromagnet, accelerator high frequency accelerating cavity, magnetic field probe, magnetic substrate , Magnetic field shielding, high-frequency quenching energy gathering, electromagnetic chuck, magnetic sensitive components (such as magneto-caloric materials as switches), etc.
(2) Permanent magnet material: large coercive force (Hc) (>102A/m), large remanence Br, large hysteresis loop area, and large loss. For example, the commonly used permanent magnet materials are divided into AlNiCo permanent magnet alloy, FeCrCo permanent magnet alloy, permanent ferrite, rare earth permanent magnet material and composite permanent magnet material. Uses: The hysteresis loop is wide and fat, and it can maintain strong magnetism for a long time after magnetization.
(3) Moment magnetic material: Br=BS, Hc is not large, and the hysteresis loop is rectangular. Such as manganese magnesium ferrite, lithium manganese ferrite, etc. Its hysteresis loop is rectangular, and the residual magnetism in two directions can be used to represent the binary "0" and "1" of the computer, so it is suitable for making "memory" components. Moment magnetic materials are divided into ferrite moment magnetic materials, amorphous alloy moment magnetic materials, nanocrystalline moment magnetic materials, and microcrystalline moment magnetic materials according to their magnetic properties. Moment magnetic materials are mainly used in random access memory devices of electronic computers, and can also be used in magnetic amplifiers, transformers, pulse transformers, etc. Using this type of material as a magnetic coating can be used to make magnetic drums, magnetic disks, magnetic cards and various magnetic tapes. The remanent induction intensity Br of the moment magnetic material is very high, close to the saturation magnetic induction intensity Bs, and has a nearly rectangular hysteresis loop in the easy magnetization direction, and the moment magnetic ratio Br/Bs is usually above 85 percent .
