PREPARATION OF HIGH-COERCIVITY FINE BARIUM FERRITE POWDER

The structural and magnetic properties of the thermally activated tran sformation from nanostructural material, mechanically disordered and d ecomposed BaFe12O19 ferrite powder to pure crystalline phase, have bee n studied by x-ray diffraction, scanning electron microscopy, and vibr ating sample magnetometry analysis techniques. All experiments were pe rformed on as-milled (1000 h) in air, and in vacuum and annealed Ba-fe rrite samples (4 h at 773 and 1273 K). In parallel with the structure and particle morphology changes, we investigate the influence of heat treatment on the powder M-H hysteresis parameters in relation to the p reparation routes, i.e., powder obtained by ball milling in air and va cuum, and annealed in air or vacuum.