Polyepitaxial grain matching to study the oxidation of uranium dioxide

• Published in: Npj Materials degradation Vol. 8; no. 1; pp. 68 - 6
• Main Authors: Wasik, Jacek, Sutcliffe, Joseph, Podor, Renaud, Lewis, Jarrod, Darnbrough, James Edward, Rennie, Sophie, Akbar Hussain, Syed, Bell, Christopher, Chaney, Daniel Alexander, Griffiths, Gareth, Harding, Lottie Mae, Legg, Florence, Lawrence Bright, Eleanor, Nicholls, Rebecca, Sasikumar, Yadukrishnan, Siberry, Angus, Smith, Philip, Springell, Ross
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.07.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/544; 639/301/299/892; 639/925/357/1018; 639/925/357/551; Chemistry and Materials Science; Corrosion and Coatings; Crystal structure; Electrochemistry; Grain size; High temperature; Investigations; Laboratories; Materials Science; Nuclear fission; Nuclear fuels; Oxidation; Phase transitions; Structural Materials; Synthesis; Thin films; Tribology; Uranium; Uranium dioxide
• ISSN: 2397-2106; 2397-2106
• DOI: 10.1038/s41529-024-00479-1

Although the principal physical behaviour of a material is inherently connected to its fundamental crystal structure, the behaviours observed in the real-world are often driven by the microstructure, which for many polycrystalline materials, equates to the size and shape of the constituent crystal grains. Here we highlight a cutting edge synthesis route to the controlled engineering of grain structures in thin films and the simplification of associated 3-dimensional problems to less complex 2D ones. This has been applied to the actinide ceramic, uranium dioxide, to replicate structures typical in nuclear fission fuel pellets, in order to investigate the oxidation and subsequent transformation of cubic UO 2 to orthorhombic U 3 O 8 . This article shows how this synthesis approach could be utilised to investigate a range of phenomena, affected by grain morphology, and highlights some unusual results in the oxidation behaviour of UO 2 , regarding the phase transition to U 3 O 8 .