抄録
Composite Ba-ferrite particles containing α-Fe were made by reducing Co-Ti-Sn substituted Ba-ferrite platelet particles in hydrogen gas. The crystal structure of Ba-ferrite is represented as the stacking of S and R layer, and the α-Fe in the composite Ba-ferrite particles was considered to be introduced primarily in the S layer in the Ba-ferrite hexagonal structure. The (110) plane of the α-Fe was parallel to the c plane of the hexagonal structure. The magnetic easy direction of the particles inclined to the plane for the samples with saturation magnetization larger than 62emu/g. The remanent coercivity of the particles was increased by introducing the α-Fe in the particles. These results indicated that the prepared particles were the composite magnetic particles consisting of hard material (Ba-ferrite) and soft one (α-Fe) behaving like a exchange spring magnet.