Localization of vacancies and mobility of lithium ions in Li2ZrO3 as obtained by 6,7Li NMR

• Polycrystalline samples Li2ZrO3 with monoclinic crystal structure synthesized at different temperatures were investigated by 6,7Li NMR spectroscopy.
• Two 6,7Li NMR lines were attributed to the specific structural positions Li1 and Li2.
• The distribution of vacancies was clarified for both lithium sites.
• The activation energy and pathways of lithium diffusion in Li2ZrO3 were defined.

The 6,7Li NMR spectra and the 7Li spin–lattice relaxation rate were measured on polycrystalline samples of Li2ZrO3, synthesized at 1050 K and 1300 K. The 7Li NMR lines were attributed to corresponding structural positions of lithium Li1 and Li2 by comparing the EFG components with those obtained in the first-principles calculations of the charge density in Li2ZrO3. For both samples the line width of the central 7Li transition and the spin–lattice relaxation time decrease abruptly at the temperature increasing above ~500 K, whereas the EFG parameters are averaged (〈νQ〉=42 (5) kHz) owing to thermally activated diffusion of lithium ions.

Path of lithium ion hopping in lithium zirconate Li2ZrO3. Figure optionsDownload as PowerPoint slide