Influence of sulphate ion on the electrical conductivity of lithium -boro-phosphate glasses

Abstract

The effect of Li2SO4 on the electrical conductivity of Li2O- B2O3- P2O5 glass system prepared by melt quenching technique has been studied. Frequency and temperature dependent conductivity measurements have been carried out in the frequency range of 10 Hz to 10 MHz and a temperature range of 523 K-603 K respectively. Conductivity in these glasses is governed by the incorporation of lithium salt in the macromolecular structure. It exhibits Arrhenius behavior over the entire temperature range. Addition of Li2SO4 expands the glass network. Consequently the conductivity increases while activation energy decreases. Impedance spectra of these glasses show a single semicircle indicating one type of conduction. The nature of conductivity behavior observed can be explained using Almond-West type power law with a single exponent σ (ω) = σ (0) + A ωs. The power law exponent (s) decreases with temperature. Scaling behavior has also been carried out using the reduced plots of conductivity with frequency, which suggests the ion transport mechanism remains unaffected by temperature and composition. © 2009 IOP Publishing Ltd.