It was found that the ionic conductivity increased monotonically by 4 orders of magnitude, from 3 x 10-8 to 5 x 10-4S/cm, when CuI was gradually replaced by AgI; with no minimum at intermediate concentrations. The results could be explained in terms of a degenerate mixed-cation effect, with differing trends for Ag and Cu mobile cations.

A.Bolotov, E.Bychkov, Y.Gavrilov, Y.Grushko, A.Pradel, M.Ribes, V.Tsegelnik, Y.Vlasov: Solid State Ionics, 1998, 113-115, 697-701