LI-7 NMR RELAXATION IN A LITAO3 SINGLE-CRYSTAL

The relaxation rate (T1(-1)) of Li-7 in LiTaO3 has been investigated as a function of temperature in the range of 160 - 400 K with a pulse NMR spectrometer operating at 4.7 T. The rate was observed to increase linearly with increasing temperature. This relaxation behavior turns out to be different from that previously reported for a powder sample, where T1(-1)) was independent of temperature and was considered to be due to the impurity effect. This linear temperature dependence of the relaxation rate in a single crystal may well be accounted for by the direct process of scattering with a single phonon. Since our measurement was made with a single crystal sample with no appreciable impurities, the present result represents a more reliable feature of the intrinsic behavior of the relaxation process in LiTaO3.