Structure and electrical conductivity of new Li2O–CeO2–B2O3 glasses

Fourier transformation infrared spectra, density and DC electrical conductivity of 30Li2O · xCeO2⋅(70 − x)B2O3 glasses, where x ranged between 0 and 15 mol%, have been investigated. The results suggested that CeO2 plays the role of network modifier up to 7.5 mol%. At higher concentrations it plays a dual role; where most of ceria plays the role of network former. The density was observed to increase with increasing CeO2 content. The effect on density of the oxides in the glasses investigated is in the succession: B2O3 < Li2O < CeO2. Most of CeO2 content was found to be associated with B2O3 network to convert BO3 into B O4− units. The contribution of Li+ ions in the conduction process is much more than that due to small polarons. The conductivity of the glasses is mostly controlled by the Li+ ions concentration rather than the activation energy for CeO2 > 5 mol%. Lower than 5 mol% CeO2 the conductivity is controlled by both factors. The dependence of W on BO4− content supports the idea of ionic conduction in these glasses.