Superionic compound Li3Sc2(PO4)3: NMR spectra and nuclear magnetic relaxation
| Autor: | I.S. Pronin, A.A. Vashman, S.E. Sigaryov |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Carbon-13 NMR satellite
Relaxation (NMR) Analytical chemistry Spin–lattice relaxation chemistry.chemical_element General Chemistry Quadrupole splitting Condensed Matter Physics NMR spectra database Nuclear magnetic resonance chemistry Condensed Matter::Strongly Correlated Electrons General Materials Science Phosphorus-31 NMR spectroscopy Transverse relaxation-optimized spectroscopy Lithium |
| Zdroj: | Solid State Ionics. 58:201-215 |
| ISSN: | 0167-2738 |
| DOI: | 10.1016/0167-2738(92)90120-e |
| Popis: | The 6,7 Li and 31 P NMR spectra and the 7 LI, 31 P spin-lattice relaxation, as well as electrical conductivity and thermal properties have been studied for powder samples of the Li 3 Sc 2 (PO 4 ) 3 superionic conductor over a wide temperature range. The quadrupole splitting parameters of the 7 Li NMR spectra and the 7 Li spin-lattice relaxation rate, T 1 −1 , are changed abruptly in the vicinity of phase transition at ⋍530 K. In the high-temperature range the 31 P spin-lattice relaxation rate is controlled by a translation motion of lithium ions, while in the low-temperature range it is controlled by a spin diffusion to paramagnetic impurities. A “frozen” EFG model is suggested, which allows to explain a quadrupole structure observed for the 7 Li NMR spectra under fast motion of lithium ions over structurally equivalent sites. The 7 Li 7 Li dipolar relaxation mechanism at a distance close to the sum of the radii of two lithium ions is used to explain T 1 −1 values of 7 Li. Three types of lithium ion motion are defined and the corresponding activation energy values have been determined. Anomalous temperature behavior of the 7 Li NMR spectra intensity that does not follow the Curie law have been found. Lack of a qualitative agreement between the X-ray data and the parameters of the 7 Li NMR spectra observed is discussed. |
| Databáze: | OpenAIRE |
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