Article contents
X-ray Absorption Studies of Vanadium Valence and Local Environment in Borosilicate Waste Glasses
Published online by Cambridge University Press: 21 March 2011
Abstract
XANES and EXAFS data were collected and analyzed to characterize vanadium in borosilicate glasses used for immobilization of sulfur-containing nuclear wastes. Earlier studies suggested that adding vanadium to the melt improves sulfur solubility. Data are presented for a variety of borosilicate glasses, some containing sulfur and some sulfur-free, that have V2O5 concentrations as high as 12 wt%, and for crystalline vanadium sulfide, silicate, and oxide standards. The data for all glasses investigated indicate that most or all vanadium has a +5 valence and is tetrahedrally coordinated by oxygen atoms. Both XANES and EXAFS also show that glasses synthesized under reducing conditions can have pentacoordinated V+4 populations up to approximately 20 to 25% of all vanadium present with the remainder being V+5O4. There is no evidence from XANES or EXAFS of V-S bonds in any of the glasses investigated.
- Type
- Research Article
- Information
- Copyright
- Copyright © Materials Research Society 2002
References
REFERENCES
- 2
- Cited by