TRANSPORT-PROPERTIES OF SEMICONDUCTING TERNARY VANADATE GLASSES

Measurements are reported for the electrical dc conductivity of the semiconducting vanadium tellurite glasses containing P2O5, Sb2O3, or Bi2O3 in the temperature range 80-450 K. The experimental data have been analyzed in the light of existing theoretical models. It has been observed that the general behavior of the electrical conductivity is similar for all glass compositions. The high temperature conductivity data are consistent with Mott's models of phonon-assisted polaronic hopping in the nonadiabatic regime, while at low temperatures variable range hopping is valid. The small polaron hopping model of Schnakenberg is the best model to interpret the temperature dependence of the activation energy and the conductivity in the entire temperature range. The percolation model applied to the polaron hopping regime is also found to be consistent with the temperature dependence of the conductivity data at high and low temperatures. The various parameters obtained by fitting these models to the experimental data are found to depend on glass forming oxides other than the vanadium oxide. © 1995 American Institute of Physics.