Multiple acoustic and optical phonon-assisted hopping in oxide glasses containing transition metal ions

Oxide glasses containing transition metal ions usually exhibit electrical conductivity due to polaron hopping. An interpretation of d/c conductivity data in 50P₂O₅50V₂O₅, 40P₂O₅60V₂O₅, 50P₂O₅50FeO, and 50TeO₂40V₂O₅10Fe₂O₃ semiconducting oxide glasses is attempted by fitting the Gorhan–Bergeron and Emin model parameters. Their model is much more general than those usually employed to interpret experimental electrical conductivity data and takes into account multiphonon interactions with optical as well as acoustic phonons. The Holstein criterion of non-adiabatic hopping is verified as well.