Infrared absorption study of Fe2O3–CaO–SiO2 glass ceramics

The ceramic glasses were prepared from extra pure reagents of Fe2O3, CaO and SiO2 powders. The 15 g batch was melted at 1550°C for 2 h in a platinum crucible. The glass structure was obtained by pouring the melt into a copper plate and pressing quickly by another copper plate. The glass structure was checked by XRD. IR studies were first made in ceramic glasses for various Fe contents. The 19.5Fe2O3·40.25CaO·40.25SiO2 glass sample was annealed at 750°C under hydrogen atmosphere. In the annealed sample, new vibration bands were observed which were absent in the untreated samples. It was observed that the new peaks are mainly due to the formation of β-CaSiO3 (wollastonite) phases.