Dielectric and electrical transport properties of alkaline earth vanadate glasses

Abstract

Glasses formed from transition metal oxides have shown tailorable electrical and optical properties depending on the valence state and individual element. Vanadate glasses have received specific attention for their high conductivities as compared to most glass families. In this study, the frequency-dependent capacitance and direct current (dc) conductivity properties of alkaline earth vanadate glasses were investigated. Glasses in the xSrO–(100 − x)V₂O₅ and xBaO–(100 − x)V₂O₅ systems, where x = 30, 40, and 50 in mol%, were prepared via melt-quench synthesis. Capacitance measurements were used to calculate dielectric constants, dielectric loss, and alternating current (ac) conductivity for each sample. Dielectric constants varied between 10–13 and 14–16 for SrO–V₂O₅ and BaO–V₂O₅ glasses, respectively, at 1 MHz. Current measurements were made as a function of temperature and voltage for each glass sample. A strong dependence on vanadate content was noted where temperature had a less strong effect. Activation energies were calculated to describe electrical transport mechanisms. All samples showed activation energies governed by electron hopping mechanisms. Such vanadate glasses have properties suitable for applications as cathode materials for batteries, solid state electrolytes, and conductive glass paste with potential for electro-optic effects involving nonlinear processes.