(23)Na multiple-quantum MAS NMR of the perovskites NaNbO(3) and NaTaO(3). - Université de Rennes Accéder directement au contenu
Article Dans Une Revue Physical Chemistry Chemical Physics Année : 2006

(23)Na multiple-quantum MAS NMR of the perovskites NaNbO(3) and NaTaO(3).

Résumé

The distorted perovskites NaTaO(3) and NaNbO(3) have been studied using (23)Na multiple-quantum (MQ) MAS NMR. NaTaO(3) was prepared by high temperature solid state synthesis and the NMR spectra are consistent with the expected room temperature structure of the material (space group Pbnm), with a single crystallographic sodium site. Two samples of NaNbO(3) were studied. The first, a commercially available sample which was annealed at 900 degrees C, showed two crystallographic sodium sites, as expected for the room temperature structure of the material (space group Pbcm). The second sample, prepared by a low temperature hydrothermal method, showed the presence of four sodium sites, two of which match the expected room temperature structure and the second pair, another polymorph of the material (space group P21ma). This is consistent with powder X-ray diffraction data which showed weak extra peaks which can be accounted for by the presence of this second polymorph. Density functional theory (DFT) calculations support our conclusions, and aid assignment of the NMR spectra. Finally, we discuss the measured NMR parameters in relation to other studies of sodium in high coordination sites in the solid state.
Fichier principal
Vignette du fichier
b604520k.pdf (299.98 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-00863177 , version 1 (18-09-2013)

Identifiants

Citer

Sharon E. Ashbrook, Laurent Le Pollès, Régis Gautier, Chris J. Pickard, Richard I. Walton. (23)Na multiple-quantum MAS NMR of the perovskites NaNbO(3) and NaTaO(3).. Physical Chemistry Chemical Physics, 2006, 8 (29), pp.3423-31. ⟨10.1039/b604520k⟩. ⟨hal-00863177⟩
226 Consultations
573 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More