Moment magnetic material refers to a ferrite material with a rectangular hysteresis loop, as shown in Figure 4. Hysteresis loop refers to the closed cycle curve experienced when the external magnetic field increases to the saturation field strength+Hs, changes from+Hs to - Hs and then returns to+Hs, and the Magnetic flux density of the magnetic material correspondingly changes from+Bs to - Bs and then returns to+Bs. The most commonly used moment magnetic materials include magnesium manganese ferrite Mg MnFe2O4 and lithium manganese ferrite Li MnFe2O4, among others

This type of material is mainly used as memory cores for various types of electronic computers, and has also been widely used in automatic control, radar navigation, space navigation, information display, and other fields.

Although there are many new types of memory emerging, magnetic memory (especially magnetic core memory) still plays an extremely important role in computing technology due to the abundant raw materials, simple process, stable performance, and low cost of ferrite moment magnetic materials.