1D NUTATION MMR OF LI-7 IN LITAO3 AND LINBO3 SINGLE-CRYSTALS AND POWDERS

1D nutation method is applied to study the electric quadrupole interac tion for the Li-7 (I=3/2) nucleus in LiTaO3 as well as LiNbO3 single c rystals and powders by using an FT NMR spectrometer. A series of spect ra were obtained with the increasing rf pulse length. The quadrupole c oupling constant and asymmetry parameter of Li-7 are determined in bot h crystals and powders from the dependence of the central line intensi ty as a function of the excitation pulse length. The values determined are in good agreement with previous results obtained from the NMR rot ation patterns of the Li-7 nucleus in LiTaO3 and LiNbO3 single crystal s.