The lattice sites of ion-implanted Li atoms were studied as a function of implantation temperatures of between ambient and 770K. Measurements were made, of the channelling and blocking patterns of the α-particles emitted during the radioactive decay of implanted 8Li ions, in order to determine the Li lattice sites. It was found that, at temperatures below 700K, the Li atoms occupied mainly interstitial sites in the centre of the c-axis hexagons; at positions c/4 and 3c/4, where c was the lattice constant in the c-axis direction. At about 700K, the Li began to diffuse; and presumably interacted with vacancies which were created during implantation. This led to the formation of substitutional Li above 700K. An activation energy of about 1.7eV was deduced for the interstitial Li diffusion.

Lattice Site Location Studies of Ion Implanted 8Li in GaN. M.Dalmer, M.Restle, M.Sebastian, U.Vetter, H.Hofsäss, M.D.Bremser, C.Ronning, R.F.Davis, U.Wahl, K.Bharuth-Ram, Isolde: Journal of Applied Physics, 1998, 84[6], 3085-9