PREPARATION OF Fe/GLASS COMPOSITE BY REDUCTION OF Na2O– Fe2O3–B2O3–SiO2–ZnO GLASS AND GLASS CERAMICS

In the present study, the feasibility of ?-Fe ferromagnetic phase formation in glass and glass-ceramic by reduction in hydrogen atmosphere have been investigated. The glass with the composition of 35Na2O–24Fe2O3–20B2O3– 20SiO2–1ZnO (mol %) was melted and quenched by using a twin roller technique. As quenched glass flakes were heat treated in the range of 400-675 °C for 1-2 h in hydrogen atmosphere, which resulted in reduction of iron cations to ?-Fe and FeO. The reduction of iron cations in glass was not completely occurred. Saturation magnetization of these samples was 8-37 emu g -1. For the formation of glass ceramic, As quenched glass flakes heat treated at 590 °C for 1 h. Heat treatment of glass ceramic containing magnetite at 675°C in hydrogen atmosphere for 1 h led to reduction of almost all of the iron cations to ?-Fe. Saturation magnetization of this sample increased from 19.8 emu g -1 for glass ceramic to 67 emu g -1.