Mixed electronic-ionic conductivity in vanadate oxide glasses containing alkaline ions

The conductivity of glasses in 50V2O5-(50-x)P2O5-xA2O (A = Li, Na, K, Rb) systems was investigated as a function of composition. In vanadate-phosphate glasses containing various alkali ions, the conductivity decreases with increasing alkali ion content. The decrease in conductivity is larger for heavier alkali ions and reaches more than seven orders of magnitude in the case of glass containing 40 mol % of Rb2O. Only glasses containing lithium exhibit relatively small conductivity changes - less than one order of magnitude - and an increase for high lithium contents.