Structural studies of NaPO3-AlF3 glasses by high-resolution double-resonance nuclear magnetic resonance spectroscopy.
BRADTMÜLLER, Henrik; ZHANG, Long; ARAUJO, Carla C.; ECKERT, Hellmut; MÖNCKE, Doris; EHRT, Doris.
BRADTMÜLLER, Henrik; ZHANG, Long; ARAUJO, Carla C.; ECKERT, Hellmut; MÖNCKE, Doris; EHRT, Doris.
 Abstract: The local structure of the model glasses (NaPO3)1-x-(AlF3)x (0 = x = 0.4), prepared by standard melt-cooling, was extensively investigated by high-resolution solidstate nuclear magnetic resonance (NMR) including advanced double-resonance techniques. This glass system offers the opportunity of studying five different heteronuclear distance correlations (Na-F, Na-P, P-F, Al-F, and P-Al) by 10 distinct double-resonance experiments, involving all of the constituent elements present. 27Al MAS-NMR data indicate that aluminum is predominantly six-coordinated. According to 27Al{31P} and 27Al{19F} rotational-echo double-resonance (REDOR) spectroscopic results, two to three Al-F and three to four Al-O-P linkages occur in these glasses, independent of composition x. 19F MAS-NMR spectra show the presence of terminal P-bound and Al-bound fluorine species. A small amount of fluorine bridging to two aluminum octahedra, which could be assigned based on 19F{27Al} and 19F{31P} REDOR experiments, was also detected. 19F{23Na} REDOR experiments indicate that the Al-bound terminal F atoms interact significantly more strongly with sodium ions than the P-bonded terminal F atoms, which is consistent with local charge considerations. On the basis of the detailed quantitative dipole-dipole coupling information obtained, a comprehensive structural model for these glasses is presented. | |
| Journal of Physical Chemistry C |
| v. 122, n. 37, p. 21579-21588 - Ano: 2018 |
| Fator de Impacto: 4,484 |
| http://dx.doi.org/10.1021/acs.jpcc.8b06162 |  @article={002903965,author = {BRADTMÜLLER, Henrik; ZHANG, Long; ARAUJO, Carla C.; ECKERT, Hellmut; MÖNCKE, Doris; EHRT, Doris.},title={Structural studies of NaPO3-AlF3 glasses by high-resolution double-resonance nuclear magnetic resonance spectroscopy},journal={Journal of Physical Chemistry C},note={v. 122, n. 37, p. 21579-21588},year={2018}} |