Experimental studies of dielectric relaxation and thermally activated a.c. conduction in Se90Cd10-xSbx (2 ≤ x ≤ 8) chalcogenide glassy alloys using correlated barrier hopping model

Se90Cd10-xSbx (x = 2, 4, 6, 8) chalcogenide semiconducting alloys were prepared by melt quench technique. The prepared glassy alloys have been characterized by technique such as SEM and energy dispersive X-ray. Dielectric properties and a.c. conductivity of prepared glassy alloys have been measured in the frequency range 5 x 10(2)-1 x 10(5) Hz and in temperature range 303-328 K. The analysis of experimental results indicate that dielectric constant (epsilon'), dielectric loss factor (epsilon aEuro(3)) and a.c. conductivity sigma(ac)(omega) are temperature, frequency and concentration dependent. The frequency dependence of sigma(ac)(omega) is found to be linear and obey the power law omega(s) where s aecurrency sign 1. A strong dependence of sigma(ac)(omega) and exponent s on temperature can be explained on the basis of correlated barrier hopping model. The maximum barrier height W-m has been calculated and results are found to be in good agreement with theory of hopping of charge carrier over potential barrier as per the theory proposed by Elliot for chalcogenide semiconductors.