Thermal, structural and optical properties of tungsten-fluorophosphate glasses and glass-ceramics with high lead fluoride contents
Eu3+-doped lead fluorophosphate glass samples were prepared in the ternary system (40-x)NaPO3-xWO3-60PbF2 by the melt-quenching method. The influence of the NaPO3/WO3 ratio on the thermal and structural properties as well as on the ability of these compositions to crystallize as glass-ceramics conta...
| Autores: | , , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | Brasil |
| Recursos: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/296851 |
| Acesso em linha: | http://dx.doi.org/10.1016/j.omx.2023.100269 https://hdl.handle.net/11449/296851 |
| Access Level: | acceso abierto |
| Palavra-chave: | Europium Glass Lead fluoride Phosphate Tungsten |
| Resumo: | Eu3+-doped lead fluorophosphate glass samples were prepared in the ternary system (40-x)NaPO3-xWO3-60PbF2 by the melt-quenching method. The influence of the NaPO3/WO3 ratio on the thermal and structural properties as well as on the ability of these compositions to crystallize as glass-ceramics containing lead fluoride phase β-PbF2 was investigated. Thermal properties and characteristic temperatures were determined by DSC and used to define suitable heat-treatment temperatures for selective crystallization. The corresponding crystalline phases and average crystallite sizes were determined by X-ray diffraction. Structural changes versus composition were also studied by Raman spectroscopy. UV-visible absorption spectra were used to determine the bandgap energies versus composition. Specific compositions exhibiting β-PbF2 crystallization were selected and Eu3+ emission spectra were used to check the Eu3+ environment and crystallization state as a function of heat-treatment conditions and glass composition. The results suggest that progressive β-PbF2 crystallization promotes a higher symmetry and lower phonon energy environment of Eu3+ resulting in longer excited state lifetimes only for WO3 richer compositions. |
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