摘要 : The spin-lattice relaxation time, T_1, for ~7Li has been measured in LiCoO_2 and Li_xNiO_2 (x = 1, 0.5) from 77 K to 680 K. The data in the high temperature region are interpreted by the relaxation mechanism of the diffusive motio... 展开 The spin-lattice relaxation time, T_1, for ~7Li has been measured in LiCoO_2 and Li_xNiO_2 (x = 1, 0.5) from 77 K to 680 K. The data in the high temperature region are interpreted by the relaxation mechanism of the diffusive motion of Li+ ion defects. The activation energy for the diffusion of the Li~+ in LiCoO_2 and LiNiO_2 is estimated to be almost same value, 0.08 eV. From the analysis based on the fluctuating field model (BPP model) with the diffusion of Li+ defects, the dominant mechanism of the spin-lattice relaxation in LiCoO2 would be the quadrupole interaction at the high temperature region. On the other hand, the relaxation in LiNiO_2 would be governed by the magnetic dipole interaction between Li nucleus and paramagnetic Ni ions in Li layer. 收起