Electrical Conductivity of Silver Vanadium Tellurite Glasses

We have investigated mixed electronic‐ionic conduction in 0.5[ x Ag 2 O·(1 − x )V 2 O 5 ]–0.5TeO 2 glasses, where the Ag 2 O amount varies over a range of 5–40 mol%. The glass samples have been prepared by quenching the melt. The ac conductivity has been measured at frequencies from 10 Hz to 100 kHz and temperatures of 300–425 K. The data indicate that the conduction mechanism changed from being predominantly electronic to ionic for Ag 2 O contents of >27.5 mol%. This transition is due to the change in glass structure, which affects both electronic‐ and ionic‐transport properties. The electronic dc conductivity results have been analyzed in terms of a small polaron‐hopping model.