MAGNETIC PROPERTIES OF STRONTIUM FERRITE PREPARED USING SUBMICRON-SIZED SrFe_(12-x)Al_xO_(19) POWDERS

摘要

The glass samples were obtained by melting of the oxides mixture SrO-Fe_2O_3-B_2O_3-(Al_2O_3) at 1200-1250℃ with subsequent quenching of the melt on quickly rotating steel roller. Submicron-sized Sr(Fe,Al)_(12)O_(19) particles were formed in glass-ceramic matrix during the crystallization aging of glass. The aging temperature T_(ag) varied in the range 650-950℃. 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℃. The aged samples exhibit coercivity value up to 8 kOe.