PREPARATION OF HIGH-COERCIVITY FINE BARIUM FERRITE POWDER

The structural and magnetic properties of the thermally activated transformation from nanostructural material, mechanically disordered and decomposed BaFe12O19 ferrite powder to pure crystalline phase, have been studied by x-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry analysis techniques. All experiments were performed on as-milled (1000 h) in air, and in vacuum and annealed Ba-ferrite 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 preparation routes, i.e., powder obtained by ball milling in air and vacuum, and annealed in air or vacuum.