Role of Additives (Cd and Ge) on the Ac Conductivity and Dielectric Relaxation of Se70Te30 Glassy Alloy

Abstract

The effect of additives (Cd and Ge) on a.c conductivity and dielectric properties of Se70Te30 glassy alloy at temperature range 300 K-350 K and frequency range 1 KHz-5 MHz has been studied. Experimental results indicate that the a.c conductivity and dielectric parameters are temperature, frequency and impurity dependent. The a.c conductivity in the aforesaid frequency range is found to obey the ωs law. A strong dependence of a.c conductivity and exponent s in the entire temperature and frequency range contradicts quantum- mechanical tunneling (QMT) model and can be interpreted in terms of the correlated barrier hopping (CBH) model .The temperature and frequency dependence of the dielectric parameters are also studied and results agrees by the theory of hopping of charge carriers over potential barrier as suggested by Elliott in chalcogenide glasses. The variation of above mentioned properties with Cd and Ge are also investigated and results are explained in terms of lone pair configuration and covalent bond character of the studied compositions.