Electrical conduction and other related properties of silver ion doped LiF–V 2O 5–P 2O 5 glass system

Abstract

LiF–V 2O 5–P 2O 5 glasses mixed with different concentrations of Ag 2O (ranging from 0 to 1.5 mol%) were prepared. The DSC studies of these glasses indicated that the glass forming ability is the highest for the glass doped with 0.6 mol% of Ag 2O. D.C. conductivity and dielectric properties over a range of temperature and also optical absorption, ESR, IR and magnetic susceptibility studies have been investigated. The optical absorption, ESR and magnetic susceptibility studies have indicated that the reduction ratio of V 4+–V 5+ ions is higher in the samples containing higher concentrations of Ag 2O. The analysis of the results of d.c. conductivity has indicated that T> θ D/2, the small polaron hopping model seems to be fit and the conduction is adiabatic in nature. These results further indicated that there is a change over of conduction mechanism from electronic to ionic at about 0.6 mol% of Ag 2O. The variations of dielectric constant and loss with temperature have been explained on the basis of space charge polarization. The low temperature part of a.c. conductivity is explained based on the quantum mechanical tunneling model.