Electroconducting polycrystalline spinel-ferrite compsn. - obtd. by sintering mixt. of spinel-type ferrite, and smaller amt. of rare earth metal oxide

摘要

Electro-conducting, polycrystalline spinel-ferrite compsn. having a low internal specific electric resistance for use in electronic device, esp. as magnetic cores for high frequency coils, is prepd. by (a) adding more than 0.01 wt.% of >=1 rare earth metal oxides to a spinel-type ferrite of formula (MO)x.(FeO)1-x.Fe2O3 (where M is >=1 divalent metal, e.g. Mn, Ni, Zn, other than Fe, and x is defined by the equation 0 = x =1), and (b) sintering the mixt. in an inert and/or weakly reducing atmos., without or with additional heating.