| 摘要 |
PURPOSE:To increase the difference B between a saturation magnetic flux density Bs and residual flux density Br and to manufacture a filter having high noise absorption characteristics by temporarily baking a mixture of specific carbonate and one selected from a group of specific oxides, mixing its pulverized powder with manganese-zinc ferrite material, and then primarily baking the mixture. CONSTITUTION:A material obtained by temporarily baking a mixture of CaCO3 and one selected from a group of V2O5, H3BO3, Bi2O3, MoO3, B2O3 and CuO, then pulverizing the mixture, and mixing the powder obtained by the pulverizing with mixture powder containing Fe2O3, MnO2 and ZnO is employed. The mixing ratio contains 0.03-3.0 mol% CaCO3, 0.01-1.0 mol% of at least one selected from a group of V2O5. H3BO3, Bi2O3. MoO3. B2O3 and CuO, 50-53 mol% Fe2O3, 24-34 mol% MoO2 and 16-23 mol% ZnO. Thus, the CaO is efficiently segregated in the boundary of grains made of the main materials thereby to reduce its loss, and its residual flux density Br is reduced. |
