The migration of Li at high temperatures was investigated, by using quasi-elastic neutron scattering techniques, in single crystals of 7Li2S. It was shown, by using polarized neutrons, that the scattering was almost completely incoherent. The data were analyzed in terms of an extended Chudley-Elliott jump diffusion model. The diffusion of Li occurred by hopping between normal tetrahedral and interstitial octahedral sites. The mean residence times on the normal Li sites were estimated to be equal to 17.3ps at 1173K, 6.7ps at 1273K and 4.3ps at 1363K.

F.Altorfer, W.Bührer, I.Anderson, O.Schärpf, H.Bill, P.L.Carron: Journal of Physics - Condensed Matter, 1994, 6[46], 9937-47