Effect of Ag2O on the conductive behaviour of silver vanadium tellurite glasses: Part II

In a previous work, 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 be 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 0.27Ag2O·0.73[YV2O5·(1−Y)TeO2] is presented. In this system, there also exists such a transition, but now, from an ionic to an electronic conductive regime. The correlated behaviour between conductivity and the mean silver-silver and vanadium-vanadium distances indicates that a concentration-based explanation is appropriate.