Peculiar Thermal Behavior of UO2 Local Stucture
| Autor: | Christoph Hennig, Kathy Dardenne, Daniel R. Neuville, E. Epifano, Damien Prieur, Joerg Rothe, Andreas C. Scheinost, Philippe Martin |
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| Přispěvatelé: | Institute of Resource Ecology, Institute of Radiochemistry, CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institute for Nuclear Waste Disposal, Institute of Resource Ecology [Dresden] (IRE), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Resource Ecology [Dresden], CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)) |
| Rok vydání: | 2018 |
| Předmět: |
Diffraction
[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th] SAX Lattice vibration 02 engineering and technology [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] 010402 general chemistry 01 natural sciences Fluorite law.invention uranium Inorganic Chemistry law Thermal Physical and Theoretical Chemistry ComputingMilieux_MISCELLANEOUS Condensed matter physics Chemistry Anharmonicity in situ 021001 nanoscience & nanotechnology Synchrotron 0104 chemical sciences Bond length Thermal shrinkage oxide 0210 nano-technology fuel |
| Zdroj: | INORGANIC CHEMISTRY INORGANIC CHEMISTRY, 2018, 57, ⟨10.1021/acs.inorgchem.8b02657⟩ Inorganic Chemistry Inorganic Chemistry, American Chemical Society, 2018, 57, ⟨10.1021/acs.inorgchem.8b02657⟩ Inorganic Chemistry, 2018, 57, ⟨10.1021/acs.inorgchem.8b02657⟩ |
| ISSN: | 1520-510X 0020-1669 |
| Popis: | Most materials expand with temperature because of the anharmonicity of lattice vibration, and only a few shrink with increasing temperature. UO2, whose thermal properties are of significant importance for the safe use of nuclear energy, was considered for a long time to belong to the first group. This view was challenged by recent in situ synchrotron X-ray diffraction measurements, showing an unusual thermal decrease of the U–O distances. This thermal shrinkage was interpreted as a consequence of the splitting of the U–O distances due to a change in the U local order from Fm3m to Pa3. In contrast to these previous investigations and using an element-specific synchrotron-based spectroscopic method, we show here that the U sublattice remains locally of the fluorite type from 50 to 1265 K, and that the decrease of the first U–O bond lengths is associated with an increase of the disorder. |
| Databáze: | OpenAIRE |
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