抄録
Since practically attainable coercivity for ferrites is relatively small in comparison with anisotropy field, many attempts have been made to enhance the coercivity by chemical and powder metallurgical methods. SrO⋅nFe3O3(n=1-6) powders were attempted to be prepare with glycine nitrate process, which is a self-combustion process using metal-nitrate/glycine complex aqueous solution. The crystal structure and magnetic properties of the powders were investigated. The powders prepared in a beaker were mixtures of a-Fe2O3 and Sr(NO3)2, which transform to M-phase with the coercivity of 7kOe after an appropriate heat-treatment. The change in coercivity by heat-treatment can be attributed to grain size of the M-phase. Spray roasting process can afford to produce Mphase directly, which shows σ(18)=56emu/g, HCJ=5.3kOe.
