The conductivity of pure crystals, or of crystals which were doped with Na+, K+, Rb+, Gd3+ or Ce3+ was studied. The thermodynamic parameters of the point defects were deduced, for temperatures ranging from 420 to 860K, by fitting the experimental data to the equations of Lidiard-Debye-Hückel theory. The enthalpies for Cl-vacancy mobility (0.30eV), Cl-interstitial mobility (0.76eV), association of a Cl vacancy with Na+ (0.53eV), K+ (0.42eV) or Rb+ (0.40eV), and ionic Frenkel defect formation (2.20eV) were used to interpret experimental results for a wide concentration range.

M.Jacquet: Journal of the Physics and Chemistry of Solids, 1986, 47[7], 707-17