Structural study of tungstate fluorophosphate glasses by Raman and X-ray absorption spectroscopy
- Instituto de Quimica, UNESP, CP 355, CEP 14801-970, Araraquara, SP (Brazil)
- Laboratoire des Materiaux Photoniques, Ba-hat t 10B, Campus de Beaulieu, Universite de Rennes I, Rennes (France)
Transparent glasses were synthesized in the NaPO{sub 3}-BaF{sub 2}-WO{sub 3} ternary system and several structural characterizations were performed by X-ray absorption spectroscopy (XANES) at the tungsten L{sub I} and L{sub III} absorption edges and by Raman spectroscopy. Special attention was paid to the coordination state of tungsten atoms in the vitreous network. XANES investigations showed that tungsten atoms are only six-fold coordinated (octahedra WO{sub 6}) and that these glasses are free of tungstate tetrahedra (WO{sub 4}). In addition, Raman spectroscopy allowed to identify a break in the linear phosphate chains as the amount of WO{sub 3} increases and the formation of P-O-W bonds in the vitreous network indicating the modifier behavior of WO{sub 6} octahedra in the glass network. Based on XANES data, we suggested a new attribution of several Raman absorption bands which allowed to identify the presence of W-O{sup -} and W=O terminal bonds and a progressive apparition of W-O-W bridging bonds for the most WO{sub 3} concentrated samples (30% molar) due to the formation of WO{sub 6} clusters.
- OSTI ID:
- 20725931
- Journal Information:
- Journal of Solid State Chemistry, Vol. 178, Issue 5; Other Information: DOI: 10.1016/j.jssc.2004.10.032; PII: S0022-4596(04)00571-7; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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