| 摘要 |
PURPOSE:To obtain superior magnetic property by adding prescribed quantity of CaO or Nb2O5 and one sort of SiO2, V2O5, Al2O3, CoO, CuO and ZrO2 after heat-treatment at higher than 900 deg.C, the calcinated material of Mn-Zn system ferrite which is prescribed constitution. CONSTITUTION:Calcinated powder which is basic constitution of 50-70mol% Fe2O3, 10-40mol% MnO, 5-30mol% ZnO is provided. At least one sort of 0.005-0.3wt% CaO, 0.005-0.25wt% Nb2O5 and 0.001-0.2wt% SiO2, 0.01-2wt% V2O5, 0.01-2wt% Al2O3, 0.01-2wt%, CoO, 0.01-0.2wt% CuO or 0.01-0.02wt% ZrO2 is performed heat-treatment previously at more than 900 deg.C in atmosphere, is composited and added to the calcinated material and is performed fine grinding, forming and sintering. By this means, additives are reacted enough each other and the additive is existed stably in grain boundary of Mn-Zn ferrite and reactivity is few, also sintering ferrite itself is controlled generation of strain. As the result, abnormal crystal texture is not generated even at high sintering temperature and low magnetic property is obtained. |
