Magnetization, Residual

Magnetization, Residual 

also remanent magnetization or remanence), the magnetization J_r that a ferromagnetic material has when the intensity of the external field is zero. Residual magnetization depends both on the magnetic properties of the material and on the previous magnetic history of the material—the nature of previous effects of a magnetic field on the material. The value of the residual magnetization of specific ferromagnetic specimens depends considerably on the shape of the specimens (this dependence is expressed by the action of the demagnetization factor). High-coercivity ferromagnets have the most stable residual magnetization. When ferromagnets are heated to a temperature above the Curie point, they lose their ferromagnetic properties and, at the same time, their residual magnetization. Mechanical vibrations also reduce the residual magnetization. Residual magnetization has extensive practical applications.