Improvement of magnetization of submicron-sized high coercivity Sm2Fe17N3 powder by using hydrothermally synthesized sintering-tolerant cubic hematite

We investigated the cause of forming of aggregates which decreases magnetization of a submicron-sized Sm2Fe17N3 powder. The aggregation was considered to be caused through sintering and growth of α-Fe particles in a hydrogen reduction treatment. We newly synthesized cubic hematite powder which has tolerance for the sintering of particles in a hydrogen reduction treatment. The aggregation of submicron-sized Sm2Fe17N3 particles was significantly reduced by using the cubic hematite as a precursor, and the magnetization was improved without decreasing the high coercivity.