Coupled effects of electronic and nuclear energy deposition in UO 2 crystals: a high-resolution XRD study carried out at the MARS beamline of the SOLEIL synchrotron facility

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 557
• Main Authors: Gutierrez, Gaëlle, Boulle, Alexandre, Menut, Denis, Georgesco, Arthur, Onofri, Claire, Béchade, Jean-Luc, Debelle, Aurélien
• Format: Journal Article
• Language: English
• Published: Elsevier 01.12.2024
• Subjects: Condensed Matter; Materials Science; Physics; strain; synchrotron; X-ray diffraction; irradiation; nuclear fuel
• ISSN: 1872-9584; 0168-583X
• DOI: 10.1016/j.nimb.2024.165491

For the first time at the SOLEIL synchrotron facility's MARS beamline, UO2 single-crystal-like samples underwent characterization, and strain depth profiles were established. Single crystals oriented along (110) and (111) were submitted to ion irradiation in the nuclear energy-loss regime (Sn) using 900 keV I2+ ions, and also with concomitant electronic energy deposition (Se) using 27 MeV Fe9+ ions. X-ray diffraction measurements were conducted at the MARS beamline, specialized for radioactive material analysis. High-angular-resolution reciprocal space maps around asymmetrical reflections and conventional symmetrical θ/2θ scans were recorded. Analysis with the RaDMaX software allowed retrieving the strain depth profiles. Results reveal that the Sn-irradiated surface layer exhibits tensile strain along its normal with no in-plane strain, that this normal strain is partially relaxed by Se. Both crystal orientations display similar behavior, but not with the same magnitude. Comparison with polycrystals indicates a more pronounced strain relaxation in the latter case.