Structural characterization of gallium fluoride phosphate glasses by advanced solid-state NMR methods and correlation with photophysical properties

Author(s)

Gaddam, Anuraag ; Galleani, Gustavo ; Reis, Vitor de Lima ; de Camargo, Andrea S. S. ; Eckert, Hellmut

• Document type: Journal article
• Source: Journal of the American Ceramic Society; v. 107, n. 12, p. 14-pg., 2024-08-06.

Abstract

Gallium fluoride phosphate glasses feature low refractive index, high energy radiation resistance, wide transmission range, and favorable emission characteristics of rare-earth dopants. For the development of optimized glass compositions, a fundamental understanding of these properties in terms of glass structure is sought. We report nuclear magnetic resonance (NMR) structural studies of glasses in the system xGa(PO3)(3)-(40 - x)GaF3-20BaF(2)-20ZnF(2)-20SrF(2) (x = 5, 10, 15, 20, and 25 mol%). P-31 NMR results with Ga-71 recoupling show that the network structure is dominated by P-O-Ga linkages, and no P-O-P linkages exist. Ga-71 NMR results show that Ga is mainly six-coordinated featuring a mixed fluoride/phosphate coordination. Quantitative estimates of this ligand distribution around gallium were obtained by Ga-71{P-31} spin echo double resonance (REDOR) measurements. Photophysical properties suggest changes in the Eu(III) ligand distribution toward a fluoride-dominated environment at low P/F ratio while the glass network is largely sustained by bridging oxygen atoms via P-O-Ga linkages. (AU)

• FAPESP's process: 21/06370-0 - Composition-structure-property correlations in boroncontaining bioglasses, elucidated by solid state nuclear magnetic resonance
• Grantee: Anuraag Gaddam
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
• Grantee: Edgar Dutra Zanotto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC