Structure and chemical durability of ZnO-B2O3-P2O5-R (n) O (m) glass system with Fe2O3 additive

摘要

ZnO-B2O3-P2O5-R (n) O (m) glasses containing different concentrations of Fe2O3 (ranging from 0 to 5 mol %) were prepared. A number of studies viz., glass transition temperature (T (g) ), density (alpha), thermal expansion coefficient (a), chemical durability, infrared spectroscopic and X-ray diffraction (XRD) patterns of these glasses had been carried out. The results of these studies have been analyzed in the light of different oxidation states of iron ions. The physical properties coupled with infrared spectroscopic and XRD indicates that the iron ions (when present in the concentration range, 0-2 mol %) exist mostly in trivalent state and occupy both tetrahedral and octahedral substitutional positions and are found to increase the rigidity of the glass network. However, in the concentration range of 2-5 mol %, the iron ions in the glass network seem to be existing by and large in Fe2+ state, occupying predominantly octahedral positions and are acting as modifiers.