Effects of Substituting B2O3 for P2O5 on the Structures and Properties of V2O5-P2O5 Glass Systems

V2O5-B2O3-P2O5 glasses with various compositions were prepared using a normal melt quenching technique, and their characteristics and structural properties were investigated using different techniques. Replacement of P2O5 by B2O3 was found to improve the thermal properties, chemical durability, and room-temperature conductivity. The observed variations in the properties may be correlated with changes in the internal glass network as a result of changes in the chemical composition. Vanadium ions are believed to be present in three possible valence states, namely V3+, V4+, and V5+, and the ratios of these states depend on the glass composition. The observed increases in chemical durability and room-temperature conductivity are assumed to be related to increases in the mean crosslinking density, increases in the number of bridging oxygens, and electron hopping between vanadate ions in different valence states.