NMR spectra and spin-lattice relaxation of 7Li of double Li2ZrO3 and Li2HfO3 oxides

NMR spectra and spin-lattice relaxation of 7Li for Li2ZrO3 and Li2HfO3 ion conductors have been investigated. Two types of positions occupied by lithium ions in crystal lattice, differing in the symmetry of lithium octahedral surrounding and constants of quadrupole interaction for 7Li, are established. The ratio of quadrupole interaction constants in lithium zirconate and hafnate correlates with the ratio of Zr4+ and Hf4+ ion electronegativities. Spin-lattice relaxation of 7Li in the range of 300-520 K is controlled by quadrupole interaction and vibrational motion of anionic sublattice with correlation time τQ=10-5-10-7 s