Improvement of Electrical Conductivity and Chemical Durability in Fe2O3 Doped V2O5-B2O3-P2O5 Glasses

In this study, we verified the relationship among the electrical conductivity, chemical durability, and structure of conductive vanadate glass in which Fe2+-Fe3+ and V4+-V5+ systems simultaneously coexist. We prepared samples of iron vanadium borophosphate glass with various compositions given by 78V(2)O(5)-15P(2)O(5)-7B(2)O(3)-xFe(2)O(3) (1, 5, 7.5 and 10 mol%) and analyzed the electrical conductivity, chemical durability, FTIR spectra, thermal properties, density, and molar volume. The results indicated that the addition of Fe2O3 improved the electrical conductivity, chemical durability, and thermal properties. The following conclusions could be drawn: Fe2+-O-P bonds or Fe3+-O-P bonds were generated in the glass structure, and Fe3+ and Fe2+ ions were located at tetrahedral and octahedral sites. Furthermore, V=O bonds were expected to be replaced with Fe-O-V and P-O-V bonds, which are stronger than double bonds, so that the complete glass structure was strong. The structural reinforcement of the glasses was additionally confirmed based on thermal and chemical properties and electrical conductivity.