Conductivity and permittivity study on silver and silver halide doped GeS2-Ga2S3 glassy system

Electrical properties of (100-2x)GeS(2-x)Ga(2)S(3-x)Agl (x=15, 20, 25, 30 at.%), 60GeS(2)-20Ga(2)S(3)-20AgX (X = Cl, Br and I) and (60GeS(2)-20Ga(2)S(3)-20Agl)(100-x)-Ag-x (x=1 and 5 at.%) chalcohalide glasses are described in terms of conductivity and permittivity. The impedance spectroscopy method was used in the frequency range of 0.1 to 10(6) Flz and in the temperature range of 258 to 393 K for our conductivity and permittivity studies. We observed all Arrhenius behavior for all samples in the case of the temperature dependence of conductivity and a large dispersion of the real part of permittivity with decreasing frequency was identified. We also found a power-law dependence of the conductivity oil the silver iodide content and an unusual almost linear dependence of the exponent alpha on the temperature. In addition, we determined frequencies f(ip) which were found to be threshold frequencies between the polarization due to the space charge accumulation and a rapid polarization process Occurring in glassy ionic conductors. (C) 2008 Elsevier B.V. All rights reserved.