DSC, ESR AND IR SPECTRAL STUDIES ON Li2O–WO3–B2O3 GLASS SYSTEM DOPED WITH VANADIUM IONS

Abstract

With in glass forming region of Li2O–WO3–B2O3 glass system, a particular composition 40Li2O–5WO3–(55–x) B2O3: xV2O5 (with x ranging from 0.2 to 0.8, all are in mol.%) is chosen. The DSC traces are obtained to identify the glass transition temperature (Tg) and the glass forming ability of all the glass samples. The ESR and IR spectra portray the local structure of the glass system and valance states of the vanadium ions in the glass matrix. As the content of V2O5 increases up to 0.6 mol.% in the glass system, a gradual conversion of vanadium ions from V5+ state to V4+ state is observed, causing the depolymerization in the glass matrix by the transformation of several glass forming units BO4 → BO3 and WO4 →WO6.