Multiphonon assisted hopping in strontium vanadate semiconducting glasses

Abstract

The temperature and compositional dependence of the electrical conductivity of semiconducting strontium vanadate glasses have been reported in the temperature range 80-500 K. It has been observed that the multiphonon assisted hopping model of small polarons in the nonadiabatic regime, which considers the strong interaction of electrons with both the optical and acoustical phonons, can interpret the temperature dependence of the conductivity data of these glasses over the entire temperature range of measurement. The parameters obtained from the fits of the experimental data to this model appear reasonable and are consistent with the glass composition. Mott's optical phonon assisted hopping model at high temperatures yields smaller values of the localization length. However, Mott's variable range hopping model can predict the low temperature data. Schnakenberg's model provided higher values of the hopping energy than the activation energy obtained at the highest temperature range.