Effect of rare earth dopant on the ac conductivity and dielectric study of GeSbSe chalcogenides glasses

Abstract

Chalcogenides glasses Ge17Sb8Se75-xErx with composition x = 0, 0.4, 0.8, 1.0 have been synthesized by conventional melt quenching technique and its dielectric and ac conductivity studies have been carried out in the temperature and frequency range 300–334 K and 5 kHz–20 kHz, respectively. Dielectric constant dependence on temperature and frequency was established for orientation polarization in the system. Dielectric loss variations with temperature and frequency were described by the conduction loss as well as single polaron hopping of charge carriers (Elliot and Shimakawa theory) for chalcogenides glasses. Correlated barrier hopping (CBH) model is used to interpret relation between temperature and frequency exponent. It was observed that with increase in frequency, both dielectric constant and dielectric loss decreases and increases with the increase in temperatures. The compositional variation in the dielectric parameters and conduction mechanism has also been explored.