Charge transfer in thin layers of glassy Ge$_{28.5}$Pb$_{14.5}$Fe$_{0.5}$S$_{56.5}$

The results of investigation of charge transfer processes in thin layers of vitreous Ge$_{28.5}$Pb$_{14.5}$Fe$_{0.5}$S$_{56.5}$ are presented. The power-law dependence of specific conductivity on frequency and a decrease of the power exponent s value with increasing temperature were found. The charge transfer is a thermally ac- tivated process with the activation energy $E_a$ = (0.64 $\pm$ 0.02) eV. The results obtained are explained within the correlated barrier hopping model (CBH) of conductivity in disordered systems. The calculated concentration of lone-pair electrons L demonstrates that the material remains in the glass-forming region.