Investigation of AC conductivity, dielectric and thermodynamics properties of Se Te Pb glassy system

Abstract

The AC conductivity and dielectric properties of amorphous Se90Te10-xPbx (x = 2, 6 at%) films have been studied in the frequency range (0.01–100 kHz)and in the temperature range (303–338 K). It is found that AC conductivity σAC(ω), dielectric constant ε1 and dielectric loss ε2 depend on frequency and temperature. The temperature dependence of both σAC(ω) and the frequency exponent s is reasonably well interpreted on the basis of correlated barrier hopping model (CBH). Values of σAC(ω) is found to increase with increasing frequency and Pb content, while values of ε1and ε2 are found to increase with temperature and decrease with frequency. The frequency exponent and dielectric loss have been analyzed to determine the maximum barrier height Wm. The two estimated values of Wm are in a good agreement with the theory of charge carriers. The relationship between the experimental measured σAC(ω), ε1, ε2 and other related parameters and chemical composition of the Se90Te10-xPbx (x = 2, 6 at%) is also discussed in terms of the average coordination number Nc and the average heat of atomization Hs for better understanding of the role of Pb addition.