Sulfur incorporation in high level nuclear waste glass: a S K-edge XAFS investigation
| Autor: | B. Brendebach, G Roth, Melissa A. Denecke, S. Weisenburger |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
History
Materials science Borosilicate glass Analytical chemistry chemistry.chemical_element Sulfur XANES Computer Science Applications Education X-ray absorption fine structure chemistry.chemical_compound symbols.namesake chemistry K-edge Sodium sulfate symbols ddc:620 Spectroscopy Raman spectroscopy Engineering & allied operations |
| Zdroj: | Journal of physics / Conference Series, 190, 012186/1-6 |
| ISSN: | 1742-6588 1742-6596 |
| DOI: | 10.5445/ir/120081730 |
| Popis: | We perform X-ray absorption fine structure (XAFS) spectroscopy measurements at the sulfur K-edge to elucidate the electronic and geometric bonding of sulfur atoms in borosilicate glass used for the vitrification of high level radioactive liquid waste. The sulfur is incorporated as sulfate, most probably as sodium sulfate, which can be deduced from the X-ray absorption near edge structure (XANES) by fingerprint comparison with reference compounds. This finding is backed up by Raman spectroscopy investigation. In the extended XAFS data, no second shell beyond the first oxygen layer is visible. We argue that this is due to the sulfate being present as small clusters located into voids of the borosilicate network. Hence, destructive interference of the variable surrounding prohibits the presence of higher shell signals. The knowledge of the sulfur bonding characteristics is essential for further optimization of the glass composition and to balance the requirements of the process and glass quality parameters, viscosity and electrical resistivity on one side, waste loading and sulfur uptake on the other side. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|