DFT Study of the Role of Al3+ in the Fast Ion-Conductor Li7-3x Al3+x La3Zr2O12 Garnet
We investigate theoretically the site occupancy of Al3+ in the fast-ion-conducting cubic-garnet Li7-3x Al3+x La3Zr2O12 (Ia-3d) using density functional theory. By comparing calculated and measured 27Al NMR chemical shifts an analysis shows that Al3+ prefers the tetrahedrally coordinated 24d site and...
| Publié dans: | Chemistry of materials : a publication of the American Chemical Society. - 1998. - 26(2014), 8 vom: 22. Apr., Seite 2617-2623 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , |
| Format: | Article |
| Langue: | English |
| Publié: |
2014
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| Accès à la collection: | Chemistry of materials : a publication of the American Chemical Society |
| Sujets: | Journal Article |
| Résumé: | We investigate theoretically the site occupancy of Al3+ in the fast-ion-conducting cubic-garnet Li7-3x Al3+x La3Zr2O12 (Ia-3d) using density functional theory. By comparing calculated and measured 27Al NMR chemical shifts an analysis shows that Al3+ prefers the tetrahedrally coordinated 24d site and a distorted 4-fold coordinated 96h site. The site energies for Al3+ ions, which are slightly displaced from the exact crystallographic sites (i.e., 24d and 96h), are similar leading to a distribution of slightly different local oxygen coordination environments. Thus, broad 27Al NMR resonances result reflecting the distribution of different isotropic chemical shifts and quadrupole coupling constants. From an energetic point of view, there is evidence that Al3+ could also occupy the 48g site with its almost regular octahedral coordination sphere. Although this has been reported by neutron powder diffraction, the NMR chemical shift calculated for such an Al3+ site has not been observed experimentally |
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| Description: | Date Revised 10.11.2023 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 0897-4756 |