Phase separation in fluorite-related U 1– y Ce y O 2– x : new insights via variable temperature neutron diffraction
dc.contributor.author | Simeone, D | en_AU |
dc.contributor.author | Deschanels, X | en_AU |
dc.contributor.author | Garcia, P | en_AU |
dc.contributor.author | Avdeev, M | en_AU |
dc.contributor.author | Ablott, TA | en_AU |
dc.contributor.author | Thorogood, GJ | en_AU |
dc.date.accessioned | 2025-04-16T02:33:56Z | en_AU |
dc.date.available | 2025-04-16T02:33:56Z | en_AU |
dc.date.issued | 2024-09-01 | en_AU |
dc.date.statistics | 2025-03-27 | en_AU |
dc.description.abstract | The phase separation in the U1-yCey O2-x system for values of y between approximately 0.34 and 0.5 observed at low temperatures (below circa 600 K) purportedly involves only fluorite structures [1,3]. Therefore, to confirm this assumption it is logical to employ high resolution diffraction techniques that can track the progression of the oxygen-sub lattice and resolve peaks that may be overlapping. In this study, the phase separation in the U0.54Ce0.46O2-x system has been revisited using variable temperature high resolution neutron diffraction on samples that are sealed under Ar to prevent a change in oxidation state when heated. As neutron scattering lengths for Unat and O do not differ to a large degree, U coherent cross section 8.903 barn vs O coherent cross section 4.232 barn, information about the oxygen sub lattice can be obtained from neutron diffraction patterns. This is not the case for X-ray diffraction which has been used for the bulk of the studies on this system. Below a critical temperature, the existence of two fluorite related structures in the miscibility gap is confirmed: a stoichiometric U0.54Ce0.46O2 phase and an oxygen-deficient U0.54Ce0.46O2-x phase. Although the former is indeed a fluorite, we show that the other end-member phase has a C-type bixbyite structure, Figure 1. © The Authors | en_AU |
dc.identifier.booktitle | Book of Abstracts ATALANTE 2024 nuclear chemistry for sustainable fuel cycles, September 1-6, 2024 - Avignon, France | en_AU |
dc.identifier.citation | Simeone, D., X., Garcia, P., Avdeev, M., Ablott, T., & Thorogood, G. J. (2024). Phase separation in fluorite-related U 1– y Ce y O 2– x : new insights via variable temperature neutron diffraction. Presentation to the 6th International ATALANTE Conference on Nuclear Chemistry for Sustainable Fuel Cycles (ATALANTE-2024) Avignon, France, September 1-6, 2024. In Book of Abstracts ATALANTE 2024 nuclear chemistry for sustainable fuel cycles, September 1-6, 2024 - Avignon, France, (pp. 111-112). Retrieved from: https://atalante2024.org/ATALANTE-2024-talks-BoA.pdf | en_AU |
dc.identifier.conferenceenddate | 2024-09-06 | en_AU |
dc.identifier.conferencename | 6th International ATALANTE Conference on Nuclear Chemistry for Sustainable Fuel Cycles (ATALANTE-2024) | en_AU |
dc.identifier.conferencestartdate | 2024-09-01 | en_AU |
dc.identifier.pagination | 111-112 | en_AU |
dc.identifier.uri | https://atalante2024.org/ATALANTE-2024-talks-BoA.pdf | en_AU |
dc.identifier.uri | https://apo.ansto.gov.au/handle/10238/16142 | en_AU |
dc.language.iso | en | en_AU |
dc.publisher | CEA | en_AU |
dc.subject | Fluorite | en_AU |
dc.subject | Neutron diffraction | en_AU |
dc.subject | Temperature range | en_AU |
dc.subject | Crystal lattices | en_AU |
dc.subject | Separation processes | en_AU |
dc.subject | Cross sections | en_AU |
dc.subject | Oxygen | en_AU |
dc.subject | X-ray diffraction | en_AU |
dc.subject | Substoichiometry | en_AU |
dc.subject | Cerium | en_AU |
dc.title | Phase separation in fluorite-related U 1– y Ce y O 2– x : new insights via variable temperature neutron diffraction | en_AU |
dc.type | Conference Abstract | en_AU |