A theoretical study was made of this halide. Inter-ionic potentials were fitted to experimental data, and the resultant potentials were used to calculate the defect behavior. The formation energies of basic defects were obtained and were used to predict intrinsic disorder and to calculate activation energies for ion migration. With regard to the formation energies of defects, it was concluded that the most likely intrinsic defect disorder would involve the formation of Li and F vacancy pairs. However, at higher temperatures, Li and F Frenkel pairs might be formed since their energies were also relatively low. Ion migration also depended upon the intrinsic disorder and it was concluded that, at low temperatures, the predominant process would be F migration via the vacancy mechanism. Thus, ionic conductivity at these temperatures might be due mainly to F. At higher temperatures, the existence of Li and F interstitials could lead to Li migration via the co-linear interstitialcy mechanism, and F migration via the interstitial mechanism. Additional contributions to the conductivity could arise from these processes. One result of these facts was that it was possible that the present halide might exhibit properties that were similar to those of a super-ionic conductor.

R.A.Jackson, M.E.G.Valerio, J.F.De Lima: Journal of Physics - Condensed Matter, 1996, 8[50], 10931-7