Modeling Ti/Ge Distribution in LiTiGe(PO) NASICON Series by P MAS NMR and First-Principles DFT Calculations.
Ti/Ge distribution in rhombohedral LiTiGe(PO) NASICON series has been analyzed by P magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy and first-principles density functional theory (DFT) calculations. Nuclear magnetic resonance is an excellent probe to follow Ti/Ge disorder, as...
| Publicado en: | Journal of the American Chemical Society Vol. 138; no. 30; pp. 9479 - 9487 |
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| Autores principales: | , , |
| Formato: | Artículo |
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American Chemical Society
8/3/2016
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=117619359&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 117619359 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 8/3/2016 vid: 138 iid: 30 pid: 997 pub: American Chemical Society artinfo: ui: 117619359 10.1021/jacs.6b03583 ppf: 9479 ppct: 8 formats: tig: atl: Modeling Ti/Ge Distribution in LiTiGe(PO) NASICON Series by P MAS NMR and First-Principles DFT Calculations. aug: au: Diez-Gómez, Virginia Arbi, Kamel Sanz, Jesús affil: Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (ICMM-CSIC), Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain su: Nuclear magnetic resonance Hematite Magic angle spinning Density functional theory X-ray diffraction sug: subj: Nuclear magnetic resonance Hematite Magic angle spinning Density functional theory X-ray diffraction ab: Ti/Ge distribution in rhombohedral LiTiGe(PO) NASICON series has been analyzed by P magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy and first-principles density functional theory (DFT) calculations. Nuclear magnetic resonance is an excellent probe to follow Ti/Ge disorder, as it is sensitive to the atomic scale environment without long-range periodicity requirements. In the samples considered here, PO units are surrounded by four Ti/Ge octahedra, and then, five different components ascribed to P(OTi), P(OTi)(OGe), P(OTi)(OGe), P(OTi)(OGe), and P(OGe) environments are expected in P MAS NMR spectra of R3̅c NASICON samples. However, P MAS NMR spectra of analyzed series display a higher number of signals, suggesting that, although the overall symmetry remains R3̅c, partial substitution causes a local decrement in symmetry. With the aid of first-principles DFT calculations, 10 detected P NMR signals have been assigned to different TiGe arrangements in the R3 subgroup symmetry. In this assignment, the influence of octahedra of the same or different R(PO) structural units has been considered. The influence of bond distances, angles and atom charges on P NMR chemical shieldings has been discussed. Simulation of the LiTiGe(PO) series suggests that detection of P environments is mainly due to the existence of two oxygen types, O1 and O2, whose charges are differently affected by Ge and Ti occupation of octahedra. From the quantitative analysis of detected components, a random Ti/Ge distribution has been deduced in next nearest neighbor (NNN) sites that surround tetrahedral PO units. This random distribution was supported by XRD data displaying Vegard's law. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2016 holdings: @attributes: islocal: N |
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