The lattice sites of ion-implanted Li atoms in 6H-, 4H- and 3C-SiC were studied. Radioactive 8Li ions (t1/2 = 0.84s) were implanted, at 60keV, into crystalline SiC samples and the channelling and blocking effects of 1.6MeV α-particles emitted during the decay were measured in order to determine the Li lattice-sites. The α-emission channelling spectra, measured along different crystallographic directions, revealed that Li occupied mainly interstitial sites with tetrahedral symmetry; centered along the c-axis atomic rows in the hexagonal lattices. In the cubic 3C-SiC structure, the Li was also located on tetrahedral interstitial sites. In 6H-SiC, the implantation temperature was varied from 200 to 823K without producing significant changes in the emission channelling spectra. Thus, no Li diffusion or Li defect interaction, resulting in a lattice-site change, occurred within this temperature range.

Lattice Site Location of Ion-Implanted 8Li in Silicon Carbide. S.Virdis, U.Vetter, C.Ronning, H.Kröger, H.Hofsäss, M.Dietrich, Isolde: Journal of Applied Physics, 2002, 91[3], 1046-52