The spin lattice relaxation rates and absorption spectra of 7Li in crystalline and vitreous samples were measured between room temperature and 800K. At low temperatures, the predominant contribution to the relaxation rate was due to spin-phonon interaction in both types of sample. In crystals, the relaxation that was caused by the diffusion of Li ions became significant at temperatures above 580K, and narrowing of the absorption line started at about 540K. In the case of glass samples, narrowing of the line began at room temperature, and the effect of Li ion diffusion upon the relaxation rate appeared at temperatures above 400K.

T.Matsuo, M.Shibasaki, N.Saito, T.Katsumata: Journal of Applied Physics, 1996, 79[4], 1903-6