Ionic conductivity of H+/Cs+ and H+/Ba+ exchange products on tantalum hydrogen phosphate

Ionic conductivity in H x M y Ta(PO 4 ) 2 . nH 2 O (M = Cs, Ba) compounds in the temperature range from 300 to 870 K was studied. At temperatures up to 670 K, cesium and barium dopants complicate carrier transport in the phosphate matrix and reduce ionic conductivity. At higher temperatures (700-870 K), samples with low hydrogen substitution levels have conductivities far higher than unsubstituted hydrogen phosphate has. Progress in substitution decreases the cationic conductivity in the compounds in question.