Abstract
To improve coercivity of Sr-Ferrite permanent magnet produced with additives of CaO and SiO2, effects of SrO and Cr2O3 additives on sintering behaviors and magnetic properties of sintered Sr-Ferrite were investigated. SrO addition was effective on dencification of Sr-Ferrite powder. This seemes to be caused by the fact that SrO additive increased the amount of a liquid phase which totally surrounded fine particles of Sr-Ferrite. Cr2O3 addition increased coercivity of Sr-Ferrite at the initial stage of the sintering process. Probably, the Cr2O3 additive interfered grain growth and increased magnetocrystalline anisotropy of Sr-Ferrite by replacing a part of Fe with Cr. Thus, the simultaneous addition of SrO and Cr2O3 to Sr-Ferrite containing CaO and SiO2 has enabled production of the sintered Sr-Ferrite magnets having high coercivity.
