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Short- and medium-range order in photothermal refractive glass revealed by solid-state NMR techniques.
FUNKE, Lena Marie; JANKA, Oliver; PÖTTGEN, Rainer; GLEBOV, Leonid; HANSEN, Michael Ryan; ECKERT, Hellmut.
Abstract: Photo-thermo-refractive (PTR) glass is an optically transparent photosensitive Na2O-ZnO-Al2O3- SiO2 glass, containing NaF and KBr additives, along with cerium, silver, tin, and antimony oxide dopants. After heating above 500 °C, UV-exposed regions of this glass produce permanent refractive index changes, resulting from precipitation of NaF nanocrystals. Short- and medium-range order of this glass system is studied via multinuclear single- and double-resonance solid-state nuclear magnetic resonance (NMR) spectroscopy in regular PTR glass and in model glasses with simplified compositions. The results, when combined with data from energy-dispersive X-ray spectroscopy, indicate that the NaF component modifies the standard aluminosilicate framework, producing small amounts of F-bonded five- and six-coordinated aluminum species. The fluoride speciation is obtained from 19F magic-angle spinning NMR spectra, supported by 19F{27Al} and 19F{23Na} dipolar recoupling experiments. The majority of fluoride within the PTR glass is found within Na-dominated local environments, which also interact strongly with the aluminum. 23Na{19F} rotational echo double resonance reveals that about 1/3 of the Na+ ions have fluoride ions in their first coordination spheres.
Journal of Physical Chemistry C
v. 123, n. 19, p. 12411-12422 - Ano: 2019
Fator de Impacto: 4,484
http://dx.doi.org/10.1021/acs.jpcc.9b02143
    @article={002943062,author = {FUNKE, Lena Marie; JANKA, Oliver; PÖTTGEN, Rainer; GLEBOV, Leonid; HANSEN, Michael Ryan; ECKERT, Hellmut.},title={Short- and medium-range order in photothermal refractive glass revealed by solid-state NMR techniques},journal={Journal of Physical Chemistry C},note={v. 123, n. 19, p. 12411-12422},year={2019}}