Magnetodielectrics

Magnetodielectrics 

magnetic materials consisting of a mixture of ferromagnetic powder and dielectric binder, which is bonded together to give a uniform conglomerate. The dielectric binder may be Bakelite, polystyrene, or rubber. In macroscopic volumes, magnetodielectrics have high electric resistance, which depends on the quantity and type of binders. Magnetodielectrics may be hard-magnetic or soft-magnetic. The soft-magnetic materials are mainly produced from fine iron carbonyl powders, molybdenum Permalloy, and Alsifer alloy with various binders. Soft-magnetic magnetodielectrics are used in the production of cores of induction coils, filters, chokes, and shell-type cores that operate at frequencies of 10⁴-10⁸ hertz.

Hard-magnetic magnetodielectrics are produced from powders of Alni alloys, Fe-Ni-Al-Co alloys (Alnico), and ferrites. The coercive force of these magnetodielectrics is lower than that of massive materials by several dozen percent, and the residual induction is almost 50 percent lower. However, these materials are increasingly used in telephone equipment and instrument-making (permanent magnets and elastic hermetic sealing devices for plug-in connectors).

REFERENCE

Tolmasskii, I. S. Metally isplavy dlia magnitnykh serdechnikov. Moscow, 1971.