Solid State Ionics, Vol.178, No.33-34, 1719-1724, 2008
DC conductivity in some alkali doped vanadotellurite glasses
Lithium-vanadium-tellurite glasses in the composition (V2O5)(0.4)-(Li2O)(x)-(TeO2)(0.6-x); 0.1 <= x <= 0.50, are investigated for room temperature density and dc electrical conductivity in the temperature range 300 K to 525 K. The density increased with increasing Li2O up to 40-mol% and then decreased for further doping of Li2O, Mixed electronic-ionic conduction has been observed in the present set of glasses. The change over of conduction mechanism from predominantly electronic to ionic is observed to be occurring at x=0.4. The high temperature (T>theta(D)/2) conductivity data obeyed Mott's small polaron hopping model (SPH) and the low temperature (T