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

Electrical properties of (100 − 2x)GeS2–xGa2S3–xAgI (x = 15, 20, 25, 30 at.%), 60GeS2–20Ga2S3–20AgX (X = Cl, Br and I) and (60GeS2–20Ga2S3–20AgI)100 − x–Agx (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 106 Hz and in the temperature range of 258 to 393 K for our conductivity and permittivity studies. We observed an 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 on the silver iodide content and an unusual almost linear dependence of the exponent α on the temperature. In addition, we determined frequencies ftp 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.