The conductivity of Ag-rich solid solutions, Ag1−xCuxI (0 < x < 0.25), was measured by using complex impedance spectroscopy at 100Hz to 15MHz and 25 to 250C. As observed in the case of undoped AgI, two conducting regions (above and below Tc) were found in the solid solutions. In spite of the large difference in the ionic radii of the Ag+ and Cu+ ions, the larger Ag+ ion dominated the overall conductivity. Arrhenius plots of the direct-current conductivity clearly revealed enhanced defect concentration and grain boundary effects in the low-temperature phase, as well as a small value of the activation energy and a softening of the AgI lattice in the high-temperature phase. The important effect of Cu-doping in AgI was considered in terms of experimental and theoretical observations.

Effect of Cu-Substitution on the Conductivity of Ag-Rich AgI–CuI Solid Solutions. P.S.Kumar, P.Balaya, P.S.Goyal, C.S.Sunandana: Journal of Physics and Chemistry of Solids, 2003, 64[6], 961-6