The order-disorder phase transition, and ionic conduction, in pure or doped samples were investigated by using X-ray diffraction and conductivity techniques. A lower conductivity in the presence of Li+, relative to the pure material, was attributed to a lattice contraction which led to a lower ion mobility. On the other hand, Tl+-doped material exhibited a higher conductivity in the high-temperature phase; with a maximum at 8mol%Tl+. This increase in conductivity was explained in terms of additional free volume which was produced by the partial replacement of Ag+ ions by the larger Tl- ions.

S.M.Nair, A.Ahmad: Journal of the Physics and Chemistry of Solids, 1997, 58[2], 331-3