Elena F Bazarkina, Stephen Bauters, Yves Watier, Stephan Weiss, Sergei M Butorin, Kristina O Kvashnina
{"title":"Exploring cluster formation in uranium oxidation using high resolution X-ray spectroscopy at elevated temperatures.","authors":"Elena F Bazarkina, Stephen Bauters, Yves Watier, Stephan Weiss, Sergei M Butorin, Kristina O Kvashnina","doi":"10.1038/s43246-025-00795-2","DOIUrl":null,"url":null,"abstract":"<p><p>Uranium dioxide (UO<sub>2</sub>) is a complex material with significant relevance to nuclear energy, materials science, and fundamental research. Understanding its high-temperature behavior is crucial for developing new uranium-based materials and improving nuclear fuel efficiency in nuclear reactors. Here we study the evolution of uranium state during the oxidation of UO<sub>2</sub> in air at temperatures up to 550 °C using the in situ X-ray absorption spectroscopy in high energy resolution fluorescence detection mode at the U M<sub>4</sub> edge, combined with electronic structure calculations. Our data reveal a complex sequence of events occurring over minutes and hours at elevated temperatures, including changes in the electronic and local structure, <i>5</i> <i>f</i> electron occupancy, the formation of U cuboctahedral clusters, and the creation of U<sub>4</sub>O<sub>9</sub> and U<sub>3</sub>O<sub>7</sub> mixed U oxide phases. These findings highlight the fundamental role of clustering processes and pentavalent uranium in both the oxidation process and the stabilization of uranium materials.</p>","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":"6 1","pages":"75"},"PeriodicalIF":7.5000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12006023/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Communications Materials","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1038/s43246-025-00795-2","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/4/17 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Uranium dioxide (UO2) is a complex material with significant relevance to nuclear energy, materials science, and fundamental research. Understanding its high-temperature behavior is crucial for developing new uranium-based materials and improving nuclear fuel efficiency in nuclear reactors. Here we study the evolution of uranium state during the oxidation of UO2 in air at temperatures up to 550 °C using the in situ X-ray absorption spectroscopy in high energy resolution fluorescence detection mode at the U M4 edge, combined with electronic structure calculations. Our data reveal a complex sequence of events occurring over minutes and hours at elevated temperatures, including changes in the electronic and local structure, 5f electron occupancy, the formation of U cuboctahedral clusters, and the creation of U4O9 and U3O7 mixed U oxide phases. These findings highlight the fundamental role of clustering processes and pentavalent uranium in both the oxidation process and the stabilization of uranium materials.
期刊介绍:
Communications Materials, a selective open access journal within Nature Portfolio, is dedicated to publishing top-tier research, reviews, and commentary across all facets of materials science. The journal showcases significant advancements in specialized research areas, encompassing both fundamental and applied studies. Serving as an open access option for materials sciences, Communications Materials applies less stringent criteria for impact and significance compared to Nature-branded journals, including Nature Communications.