AC Conductivity and Dielectric Properties of Amorphous Te42As36Ge10Si12 Glass

Te42As36Ge10Si12 chalcogenide composition was prepared by conventional melt-quenching. The ac conductivity and the dielectric properties were carried out in the frequency range 0.5 x 10(3)-4 x 10(6) Hz and temperature range 300-423 K. The analysis of the experimental results of the frequency dependence of ac conductivity sigma(ac)(omega) indicates that sigma(ac)(omega) is proportional to omega(s) where s > 1. The temperature dependence of both ac conductivity and the parameter s is reasonably well interpreted by the correlated barrier hopping model. The maximum barrier height W-m calculated from ac conductivity and the density of localized states were determined. Values of dielectric constant epsilon(1) and dielectric loss epsilon(2) were found to decrease with frequency and increase with temperature. The analysis of dielectric loss leads to determine the barrier height W-m and agrees with that proposed by the theory of hopping of charge carriers over potential barrier between charged defect states as suggested by Elliott in case of chalcogenide glasses.