PREPARATION OF NANOCRYSTALLINE BARIUM HEXAFERRITE IN A GLASS MEDIUM

Barium hexaferrite phase of composition BaO-6Fe(2)O(3) of dimensions i n the range 8.2 to 17.6 nm have been grown within a glass medium by su bjecting the latter to a suitable heat treatment. Magnetization measur ements on the resultant glass-ceramic have been carried our at tempera tures varying from 20 to 300 K. The coercive field H-c is found to be much smaller than that of bulk hexaferrite. The value of H-c increases as the temperature is reduced. Also, H-c shows an increase with the i ncrease of hexaferrite particle size. It appears that the effective an isotropy constant plays an important role in determining this behavior . (C) 1997 Acta Metallurgica Inc.