Hopping conductivity in V2O5-P2O5 glasses: Experiment and non-constant force field molecular dynamics

Glasses in xV2O5–(100-x)P2O5 system within x range from 35 to 95 mol% are obtained by a melt-quenching method and characterized by X-ray powder diffraction, atomic emission spectroscopy and red-ox titration. The dependences of density and molar volume of glasses on V2O5 concentration are linear up to 90 mol% of vanadium oxide and can be expressed via formulas: ρ = 2.64 + 0.36·xV2O5 g cm−1 and Vmol = 54.17 + 6.36·xV2O5 cm3 mol−1. The electronic conductivity of glasses is measured by both impedance spectroscopy and direct current methods. The glass composition of 95V2O5·5P2O5 shows the highest electrical conductivity value of ~1.0 × 10−4 S cm−1 at 50 °C. The concentration dependence of the conductivity is described at a qualitative level with non-constant force field molecular dynamics.