Investigations on frequency and temperature dependence of AC conductivity and dielectric parameters in Ge20Ga5Sb10S65 quaternary chalcogenide glass

Abstract

Frequency and Temperature dependence of AC conductivity and dielectric parameters viz. dielectric constant, dielectric loss for multicomponent bulk Ge20Ga5Sb10S65 chalcogenide glass sample for the temperature range 313 K–373 K and 1kHz-1 MHz frequency regime has been investigated. The values of dielectric constant ε' and dielectric loss ε" for the sample prepared by the conventional melt-quenching method were found to decrease with frequency. The value of maximum barrier height calculated from the dielectric analysis according to Guintini equation is in agreement with theory of hopping across a potential barrier as proposed by Elliot for chalcogenide glasses. The increase in AC conductivity with frequency for the investigated sample confirms correlated barrier hopping (CBH)responsible for conduction mechanism. The density of localized states and ac activation energy were estimated for the present sample. This study of dielectric properties of quaternary Ge20Ga5Sb10S65 chalcogenide glass is useful for the determination of the structure and defects in these materials and thereby understanding the mechanism of conduction in the present sample.