Magnetic Properties of Strontium Ferrite Prepared Using Submicron-Sized SrFe12-x AlxO19 Powders

The glass samples were obtained by melting of the oxides mixture SrO-Fe2O3-B2O3-(Al2O3) at 1250-1300 degree C with subsequent quenching of the melt on quickly rotating steel roller. Submicron-sized SrFe12-xAlxO19 particles were formed in glass-ceramic matrix during the crystallization aging of glass. The aging temperature Tag varied in the range 600-950 degree C. The submicron-sized hexaferrite powder was obtained by removing of the matrix phases using etching. The samples were characterized by X-ray diffraction, scanning electron microscopy and magnetization measurements. The glass-ceramic material exhibits very high coercivity value up to 10 kOe. The samples of magnets were obtained by pressing of the hexaferrite powder at RT and subsequent aging in the range 900-1200 degree C. The aged samples exhibit high coercivity value up to 8 kOe.