Study of the electrical conduction mechanism of the 70V2O5∙ 30TeO2 (mol%) pelletized glasses using the Schnakenberg model

The direct-current (DC) electrical conductivities (σ) of pelletized 70V2O5∙ 30TeO2 (mol%) glasses annealed in a H2 gas atmosphere at 473 K in the temperature range of 327–461 K were determined. Electrical conduction was explained using the Schnakenberg model, which is based on the log (σT)–T−1 relationship in the temperature region (T denotes the absolute temperature). The physical parameters (optical phonon frequency [ν0], hopping energy [WH], and disorder energy [WD]) determined using the model are as follows: ν0 = (1.15 ± 0.005–1.65 ± 0.005) × 1013 s−1, WH = 0.0722 ± 0.00005–0.296 ± 0.0005 eV, and WD = 0.0750 ± 0.00005–0.122 ± 0.0005 eV. The Schnakenberg model was suitable for interpreting the temperature dependence of the σ values in the temperature region based on these parameters. The electron-hopping distance (R) was calculated to be between 0.844 ± 0.058 and 3.71 ± 0.28 nm. The WH–R relationship showed that when the WH value decreased, the R value also decreased. WH and R indicate temperature-dependent values. This phenomenon was caused by electron hopping as a result of the following process: when the temperature decreased, the WH values decreased and the R values increased. These findings quantitatively demonstrate that a decrease in the temperature influences the alteration of the electrical conduction mechanism (from small polaron hopping to variable range hopping) by contributing to an increase in R and a decrease in WH. •The DC electrical conductivities of pelletized 70V2O5∙ 30TeO2 (mol%) glasses annealed in a H2 gas atmosphere in the temperature range of 327–461 K were measured.•The Schnakenberg model was used to describe electrical conduction in glasses.•The Schnakenberg model could adequately interpret the temperature dependence of conductivity in the temperature range 327–461 K.•The reduction in temperature influences the shift in the electrical conduction mechanism (from SPH to VRH) by increasing the electron-hopping distance and decreasing the hopping energy.