MANGANESE-ZINC FERRITE AND MANGANESE-ZINC FERRITE CORE

摘要

PROBLEM TO BE SOLVED: To provide a manganese-zinc ferrite core having high initial magnetic permeability in a wide frequency range.;SOLUTION: Manganese-zinc ferrite comprises MnO, ZnO and Fe₂O₃ as principal components, 0-0.005 wt.% SiO₂, 0.02-0.2 wt.% CaO, 0.05-0.5 wt.% MoO₃, 0.01-0.2 wt.% K₂O, 0.005-0.1 wt.% Bi₂O₃, and 0.005-0.05 wt.% Nb₂O₅ as assistant components and at least one of 0.001-0.1 wt.% B₂O₃ and 0.001-0.1 wt.% P₂O₅. When a precipitation phase containing MoO₃ and CaO is formed on the surface of a fired body of the obtained manganese-zinc ferrite and the average crystal grain size of the resulting fired body is made to be 30-100 μm and the specific resistance of the resulting fired body is made to be 20-100 Ωcm, the manganese-zinc ferrite core having ≥12,000 initial magnetic permeability when the frequency is 1 kHz and ≥12,500 initial magnetic permeability when the frequency is 150 kHz can be obtained.;COPYRIGHT: (C)2009,JPO&INPIT