Conductivity measurements were used to determine the association enthalpies of divalent impurity ions and Ag vacancies. The impurities were chosen so as to clarify the effects of ionic radius, electronic structure, and nature of the host material. The temperature dependence of the conductivity was measured in monocrystals of AgCl that were doped with V2+, Cr2+, Fe2+ or Co2+, and in monocrystals of AgBr that were doped with Mg2+, Ca2+, Sr2+, Ni2+ or Cd2+. A principal observation of the study was an apparent independence, of the association enthalpies in AgCl, with regard to the size and electronic shell configurations of the first-row transition metal ions. As expected, the association enthalpy values were found to be smaller in AgBr than in AgCl. In the case of AgBr, a marked relationship was found between the ionic polarizability and association enthalpy.

R.J.Liess, L.M.Slifkin: Journal of the Physics and Chemistry of Solids, 1996, 57[1], 101-7