Dielectric properties of vanadium phosphate glasses in a combined electric field

Abstract

The dielectric properties of vanadium phosphate glasses, composed of 70 mol% V2O5 and 30 mol% P2O5 with an addition of 1 wt% of CuO, have been measured under combined voltages simultaneously composed of dc voltages of 0, 30, 45 and 65 V, and an ac voltage of 0.5 V. Measurements were taken over a temperature range of 20–110°C and a frequency range of 10–105 Hz. The NiCr alloy electrodes used in this study were prepared by chemical vapour deposition techniques. The results of the measurements show that the conductivity and dielectric properties of the glasses could be described by a mechanism of electron hopping between energy states of the chain of molecules or by a tunneling effect. The transport of the electric charges involves movement across a potential barrier and the movement could be improved if the barrier was deformed by the dc voltage.