IR absorption spectra of lithium and silver vanadium–tellurite based glasses

The aim of the present paper is to give structural information in order to set a correlation between the electrical conductivity behavior and structures of lithium and silver vanadium–tellurite based glasses. We report our structural studies and compare the effect of the nature of the metallic cation on glasses of the form XM ₂O · (1 − X)V ₂O ₅ · 2TeO ₂ (where 0 ⩽ X < 1 and M = Li or Ag). Fourier transform infra-red (FTIR) spectra were recorded for all compositions and complementary differential scanning calorimetry (DSC) measurements and X-ray diffraction (XRD) measurements were also carried out. This paper should be considered as complementary to a previous article reporting the conductive behavior of theses glasses. In the latter we reported the obtained results on electrical conductivity studies. The results confirm the existence of a transition from a typically electronic (polaronic) conductive regimen when the molar fraction ( X) of M ₂O is equal to 0, to an ionic conductive regimen when X tends to 1. The evidence for the independent migration path for both electrons and ions was put into evidence by studying the electrical conductivity behavior in a complementary system of the form X M ₂O · (1 − X)[0.5V ₂O ₅–0.5MoO ₃] · 2TeO ₂. In this system vanadium was partially replaced by molybdenum which acts as a ‘diluting’ agent of the active centers involved in the electronic transport.