The conductive behaviour of silver vanadium–molybdenum tellurite glasses

In a previous paper, the effect of the Ag2O on the electrical conductivity of vanadium tellurite glasses of the form XAg2O·(1−X)V2O5·2TeO2 has been studied by using the impedance spectroscopy in a wide range of temperature and composition. The obtained results confirm the existence of a transition from a typically electronic (polaronic) conductive regime when the molar fraction (X) of Ag2O is equal to 0 to an ionic conductive regime when X tends to 1. This transition is characterised by a deep minimum in the electrical conductivity of about three orders of magnitude. In the present paper, a complementary study of the system of the form XAg2O·(1−X)[0.5V2O5–0.5MoO3]2TeO2 is reported. The correlated behaviour between conductivity and the mean distance between silver ions and between vanadium ions for these two systems reinforces the idea of two independent migrating paths for both electrons and ions, respectively.