PREPARATION OF Fe/GLASS COMPOSITE BY REDUCTION OF Na۲O– Fe۲O۳–B۲O۳–SiO۲–ZnO GLASS AND GLASS CERAMICS

In the present study, the feasibility of α-Fe ferromagnetic phase formation in glass and glass-ceramic by reduction in hydrogen atmosphere have been investigated. The glass with the composition of ۳۵Na ۲ O–۲۴Fe۲O۳–۲۰B ۲O۳ – ۲۰SiO ۲ –۱ZnO (mol %) was melted and quenched by using a twin roller technique. As quenched glass flakes were heat treated in the range of ۴۰۰-۶۷۵ °C for ۱-۲ h in hydrogen atmosphere, which resulted in reduction of iron cations to α-Fe and FeO. The reduction of iron cations in glass was not completely occurred. Saturation magnetization of these samples was ۸-۳۷ emu g -۱ . For the formation of glass ceramic, As quenched glass flakes heat treated at ۵۹۰ °C for ۱ h. Heat treatment of glass ceramic containing magnetite at ۶۷۵°C in hydrogen atmosphere for ۱ h led to reduction of almost all of the iron cations to α-Fe. Saturation magnetization of this sample increased from ۱۹.۸ emu g -۱ for glass ceramic to ۶۷ emu g -۱

Keywords:

Magnetite , α-Fe , Reduction , Glass , Glass Ceramic , Magnetic Composite