Short- and Medium-Range Order in Photothermal Refractive Glass Revealed by Solid-State NMR Techniques

Autor(es)

Funke, Lena Marie ^[1] ; Janka, Oliver ^[2] ; Poettgen, Rainer ^[2] ; Glebov, Leonid ^[3] ; Hansen, Michael Ryan ^[1] ; Eckert, Hellmut ^{[1, 4]}

Afiliação do(s) autor(es)

^[1] Westfalische Wilhelms Univ Munster, Inst Phys Chem, Corrensstr 30, D-48149 Munster - Germany

^[2] Westfalische Wilhelms Univ Munster, Inst Anorgan & Analyt Chem, Corrensstr 30, D-48149 Munster - Germany

^[3] Univ Cent Florida, Dept Chem, Orlando, FL 32816 - USA

^[4] Univ Sao Paulo, Inst Fis Sao Carlos, CEP 369, BR-13566590 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 123, n. 19, p. 12411-12422, MAY 16 2019.
• Citações Web of Science: 1

Resumo

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 degrees 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 F-19 magic-angle spinning NMR spectra, supported by F-19[Al-27] and F-19[Na-23] 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. Na-23[F-19] rotational echo double resonance reveals that about 1/3 of the Na+ ions have fluoride ions in their first coordination spheres. (AU)

• Processo FAPESP: 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros
• Beneficiário: Edgar Dutra Zanotto
• Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs