IONIC MOBILITY AND 19F MAS NMR SPECTRA OF LITHIUM OCTAFLUOROZIRCONATE Li4ZrF8
A. B. Slobodyuk, V. Ya. Kavun, N. A. Didenko
Institute of Chemistry, Far Eastern Division, Russian Academy of Sciences
Keywords: lithium fluorozirconates, ionic mobility, NMR spectra, 7Li, 19F, MAS
Abstract
Ionic mobility of Li4ZrF8 (I) and Li3.72Mg0.14ZrF8 (II) compounds has been studied over the temperature range of 300-420 K using 7Li, 19F broad-line NMR and NMR relaxation techniques. The fluorine sublattice in these compounds was found to be rigid, whereas in the lithium sublattice there occurs a diffusion with the activation energy of 0.2-0.3 eV. NMR data indicate the formation of lithium vacancies in solid solution II. MAS NMR of fluorine was used to determine the isotropic chemical shifts of its magnetically nonequivalent positions and to correlate these shifts with the crystal structure of Li4ZrF8.
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