Thermoanalytical, structural and ionic conductivity studies on 50Li2O–45P2O5–5Nb2O5 glass

Abstract

Thermal, structural and ionic conduction characteristics of lithium niobophosphate glass (mol% 50Li2O–45P2O5–5Nb2O5) are reported and compared with the characteristics of lithium metaphosphate glass (mol% 50Li2O–50P2O5). The presence of the second glass former (Nb2O5) not only improves the chemical durability and thermal stability but also enhances the conduction characteristics of lithium metaphosphate glass. The ionic conductivity measurements are reported in the extended temperature range i.e. above the glass transition temperature (Tg) where a non-Arrhenius temperature dependence of the ionic conductivity has been observed. The ion conduction process below Tg is governed by a well-defined activation energy whereas the conduction process above Tg is activated by at least two different phenomena discussed in the light of the structural relaxation and crystallization.