Complex impedance and structural analyses of the mixed system 40(Cu1−xAgxI)–30(Ag2O)–30(SeO2), (0.05≤x≤0.25)

Using complex impedance analysis, temperature-dependent electrical conductivity studies of various compositions of the mixed system 40(Cu1−xAgxI)–30(Ag2O)–30(SeO2), (0.05≤x≤0.25) over the temperature region 295–445 K have been carried out. All the chosen compositions of the system exhibit Arrhenius type of conductivity as a function of temperature and their activation energies for conduction lie in the range 0.27–0.42 eV. The values of ionic transport number of these materials are greater than 0.96. The presence of AgI in these materials has been inferred from the β→α phase transition of AgI, which is characterized by an endothermic peak at around 416 K in the DSC traces of these specimens. While the structural analysis carried out by means of X-ray diffraction has revealed the formation of AgI, Ag2SeO4 and new phases involving glassy and crystalline compounds, the Fourier transform infrared (FTIR) spectroscopic results have indicated the presence of SeO42−, SeO32− and Se2O72− species thus confirming the ionic nature of the phases.