Mechanism of hopping conduction in new CeO2-B2O3 semiconducting glasses

The conduction mechanism is found to be non-adiabatic in nature for glasses investigated. Mott's model for the small polaron hopping conduction between nearest-neighbors gives unreasonable values for the Ce-Ce distance and the phonon frequency of the lattice vibrations. The increase in the conductivity with temperature can be interpreted in terms of the Schnakenberg model for optical multiphonon assisted hopping process at high temperatures and single optical phonon process at the lower ones. This model gives reasonable values for the phonon frequency of the lattice vibrations, the polaron hopping energy, and slightly higher values of WD.