Estimation of the density of defect states in glassy Se_80−xTe₂₀Sn_xalloys using ac conductivity measurements

Abstract

In this paper, we have studied the temperature and frequency dependence behavior of ac conductivity in the glassy system Se 80−x Te 20 Sn x (0 x 10). All the measurements have been carried out in the frequency range 1-500 kHz and in the temperature range from room temperature to the glass transition temperature T g . The density of defect states has been determined using the correlated barrier-hopping model for all these glassy alloys. The appearance of local extrema in the density of defect states is explained in terms of the change from one-dimensional (1D) to 2D structure (from 'bundles' to 'layers') and from 2D to 3D structure (from 'layers' to 'clusters').