Eur. Phys. J. Appl. Phys. 44, 217-221 (2008)
https://doi.org/10.1051/epjap:2008171

Effect of Zn incorporation on the a.c. conductivity of glassy Se₇₀Te₃₀ alloy

¹ Department of Physics, Harcourt Butler Technological Institute, Kanpur, India
² Department of Physics, Banaras Hindu University, Varanasi, India

Corresponding author: dr_ashok_kumar@yahoo.com

Received: 10 June 2008
Revised: 21 July 2008
Accepted: 27 August 2008
Published online: 6 December 2008

Abstract

The present work reports the temperature and frequency dependence of a.c. conductivity in glassy Se₇₀Te_30−xZn_x (x = 0, 2, 4 and 6) alloys in the temperature range 300–500 K and frequency range 1 kHz. An agreement between experimental and theoretical results suggests that the a.c. conductivity behaviour of the present samples can be successfully explained by correlated barrier hopping (CBH) model. The density of defect states has been determined using this model for all the glassy alloys. The results show that bipolaron hopping dominates over single-polaron hopping in this glassy system. This is explained in terms of lower values of the maximum barrier height for single-polaron hopping.