Comparative Nuclear Magnetic Resonance Study of As-Grown and Annealed LiInSe2 Ternary Compounds

We report on a nuclear magnetic resonance study of the nonlinear crystal LiInSe2. This ternary compound shows a considerable variation of its color depending on the growth or annealing conditions. Room temperature 7Li and 115In NMR spectra of as-grown and annealed single crystalline and powdered samples have been measured. Analysis of the NMR spectra, along with the X-ray diffraction and optical spectroscopy data, leads to a conclusion that the change in color upon annealing in In2Se3 vapor is due to a change in the number of point defects.