Compositional Optimization of Emission Properties for Rare-Earth Doped Fluoride Phosphate Glasses: Structural Investigations via NMR, EPR, and Optical Spectroscopies

Autor(es)

Galleani, Gustavo ^[1] ; Doerenkamp, Carsten ^[1] ; Santagneli, Silvia ^[2] ; Magon, Claudio Jose ^[1] ; de Camargo, Andrea S. S. ^[1] ; Eckert, Hellmut ^{[1, 3]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis Sao Carlos, Ave Trabalhador Saocarlense 400, BR-13566590 Sao Carlos, SP - Brazil

^[2] Univ Estadual Paulista, Inst Quim, Rua Prof Francisco Degni 55, BR-14800060 Araraquara, SP - Brazil

^[3] Westfalische Wilhelms Univ Munster, Inst Phys Chem, Corrensstr 30, D-48149 Munster - Germany

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 123, n. 51, p. 31219-31231, DEC 26 2019.
• Citações Web of Science: 0

Resumo

A detailed structural investigation of two series of fluoride phosphate glasses with nominal compositions 20BaF(2)-20SrF(2)-20ZnF(2)-xIn(PO3)(3)-(40 - x)InF3 (x = 0, 5, 10, and 15) and 20BaF(2)-20SrF(2)-20ZnF(2)-10ScF(3)-xIn(PO3)(3)-(30 - x)InF3 (x = 0, 10, 15, 20), both doped with either 0.2 mol % Yb3+ or 0.S mol % Eu3+, has been conducted. As indicated by Raman scattering and solid- state NMR, the network structure is dominated by six-coordinated In3+, orthophosphate Q((0)()) species, and the (near) absence of P-O-P connectivity. The ligand environment of the rare-earth ions is studied by (1) Sc-45 NMR of the diamagnetic mimic Sc3+, (2) echo-detected field-sweep EPR spectra at the X-band, using Yb3+ spin probes, and (3) excitation and emission spectroscopy of Eu3+ dopants. Sc-45[P-31] rotational echo double resonance (REDOR) results, the ratio of the Eu3+ D-5(0) -> F-7(2) to (5) D-0 -> F-7(1) emission intensities, the lifetime values of the Eu3+ emitting level D-5(0), as well as the g factor measured by EPR spectroscopy consistently indicate that the fluoride ligands strongly dominate in the first coordination sphere of the rare-earth ions. This result stands in contrast to previous studies on aluminofluorophosphate glasses with similar compositions that show mixed ligation of the rare-earth ions by fluoride and phosphate ions. Thus, by substituting aluminum by its homologue indium one can achieve the original design goal of fluoride phosphate glasses, which is the creation of a framework structure dominated by oxide, while the local environment of the RE emitting ion is dominated by fluoride ligands, so as to improve their emissive properties. The results also illustrate the successful use of the previously developed combined NMR/EPR/optical characterization strategy for the design of optimized matrices for rare-earth ion emitters. (AU)

• Processo FAPESP: 17/06649-0 - Novos materiais óticos baseados em vidros e cerâmicas oxifluoretos dopados com terras-raras: estudos estruturais por ressonância paramagnética eletrônica.
• Beneficiário: Carsten Doerenkamp
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/03931-9 - Preparação de vidros e vitrocerâmicas de fluorofosfatos dopados com íons terras-raras para potencial uso como detectores de radiação.
• Beneficiário: Gustavo Galleani
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• 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
• Processo FAPESP: 18/24735-3 - Correlação entre a estrutura e as propriedades investigada por RMN multinuclear no estado sólido em materiais desordenados
• Beneficiário: Silvia Helena Santagneli
• Linha de fomento: Auxílio à Pesquisa - Regular