Dielectric relaxation behavior and conduction mechanism of Te46As32Ge10Si12 films.

Abstract

Alternating current conductivity and dielectric properties measurements have been performed on the Te46As32Ge10Si12 amorphous films at frequency and temperature ranges (0.1–100kHz)and (303–383K) respectively. The ac conductivities were analyzed by considering a power relation σacαωs (s≤1). Ac conductivity and its frequency exponent have been analyzed in the framework of various theoretical models. The non-overlapping small polaron tunneling model is found the suitable model to describe the conduction mechanism for the present glassy films. The presence of the dielectric loss peaks shift to higher frequency with increasing temperature indicate the characteristics feature of Debye-type relaxation process with strong polydispersion nature of the dielectric relaxation. The temperature dependence of the relaxation time yields the activation energy of relaxation (0.119eV). The distribution of the relaxation time is confirmed by Cole–Cole plots. Some parameters like optical dielectric constant, static dielectric constant, macroscopic relaxation time, molecular relaxation time and dielectric strength have been estimated from Cole–Cole diagrams and studied as a function of temperature.