TY  - JOUR
AU  - Murphy, Gabriel L.
AU  - Bazarkina, Elena
AU  - Rossberg, André
AU  - Silva, Clara L.
AU  - Amidani, Lucia
AU  - Bukaemskiy, Andrey
AU  - Thümmler, Robert
AU  - Klinkenberg, Martina
AU  - Henkes, Maximilian
AU  - Marquardt, Julien
AU  - Lessing, Jessica
AU  - Svitlyk, Volodymyr
AU  - Hennig, Christoph
AU  - Kvashnina, Kristina O.
AU  - Huittinen, Nina
TI  - The role of redox and structure on grain growth in Mn-doped UO2
JO  - Communications materials
VL  - 5
IS  - 1
SN  - 2662-4443
CY  - London
PB  - Springer Nature
M1  - FZJ-2025-00486
SP  - 274
PY  - 2024
AB  - Mn-doped UO2 is considered a potential advanced nuclear fuel due to ameliorated microstructural grain growth compared to non-doped variants. However, recent experimental investigations have highlighted limitations in grain growth apparently arising from misunderstandings of its redox-structural chemistry. To resolve this, we use synchrotron X-ray diffraction and spectroscopy measurements supported by ab initio calculations to cross-examine the redox and structural chemistry of Mn-doped UO2 single crystal grains and ceramic specimens. Measurements reveal Mn enters the UO2 matrix divalently as with the additional formation of fluorite Mn+2O in the bulk material. Extended X-ray absorption near edge structure measurements unveil that during sintering, the isostructural relationship between fluorite UO2 and Mn+2O results in inadvertent interaction and subsequent incorporation of diffusing U species within MnO, rather than neighbouring UO2 grains, inhibiting grain growth. The investigation consequently highlights the significance of considering total redox-structural chemistry of main and minor phases in advanced ceramic material design.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001381203000005
DO  - DOI:10.1038/s43246-024-00714-x
UR  - https://juser.fz-juelich.de/record/1037139
ER  -