Silver ionic conductivity enhancement by network former mixed in oxide-based glasses

Glasses in the binary system xAg(2)P(2)O(6)-(1-x)Ag2Te2O5 have been prepared for 0 less than or equal to x less than or equal to 1. For each composition only one glass transition temperature is observed in the temperature range of 180-220 degrees C. All glasses appear homogeneous considering their optical and electrical properties. Nevertheless, in SEM observations, some glass compositions appear to be heterogeneous after decoration following short nitric acid etching. For each composition, conductivity data obtained in the temperature range of 25-200 degrees C using impedance techniques obey an Arrhenius relationship with a composition independent pre-exponential term. Variation of the conductivity activation energy with x induces correlative variations of isothermal conductivity curves leading to an increase of the ionic conductivity of about one order of magnitude compared with linearity at 25 degrees C. This behaviour is discussed with respect to the thermodynamic properties of the glassy solutions.