TY - JOUR
T1 - Role of electronic effects on the incorporation of Cr at a Σ5 grain boundary in UO2
AU - Hong, Minki
AU - Uberuaga, Blas P.
AU - Andersson, David A.
AU - Stanek, Christopher R.
AU - Phillpot, Simon R.
AU - Sinnott, Susan B.
N1 - Funding Information:
This work was supported by the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Program, Fuels Integrated Performance and Safety Code (IPSC) project. Los Alamos National Laboratory is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the (US) Department of Energy under contract DE-AC52-06NA25396. This work was authored by a subcontractor (SRP) of the US Government under DOE Contract No. DE-AC07-05ID14517, under the Energy Frontier Research Center (Office of Science, Office of Basic Energy Science, FWP 1356). Accordingly, the US Government retains and the publisher (by accepting the article for publication) acknowledges that the US Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US Government purposes. BPU, who co-advised this work, acknowledges support by the Center for Materials at Irradiation and Mechanical Extremes, an Energy Frontier Research Center funded by DOE (Office of Science, Office of Basic Energy Sciences, 2008LANL1026).
PY - 2013
Y1 - 2013
N2 - Due to the important role of microstructure on nuclear fuel performance, it is desirable to obtain improved control of fuel microstructure. For example, Cr2O3 has been used as a grain growth promoter during the sintering of UO2; however, the influence of Cr incorporation on the bonding within the grain boundary is not well understood. Here, we quantify the energetics associated with Cr incorporation and segregation in a model UO 2 system with a Σ5 symmetric tilt grain boundary using density functional theory calculations. The results indicate that Cr prefers to reside in a U substitutional site and segregate to the grain boundary. The Bader charge analysis and the charge density difference analyses confirm that Cr forms bonds with neighboring O atoms that weaken the ionic nature of adjacent U-O bonds, especially when it occupies U substitutional site at the grain boundary. The implications of these findings for the usage of Cr2O3 as a growth promoter are discussed.
AB - Due to the important role of microstructure on nuclear fuel performance, it is desirable to obtain improved control of fuel microstructure. For example, Cr2O3 has been used as a grain growth promoter during the sintering of UO2; however, the influence of Cr incorporation on the bonding within the grain boundary is not well understood. Here, we quantify the energetics associated with Cr incorporation and segregation in a model UO 2 system with a Σ5 symmetric tilt grain boundary using density functional theory calculations. The results indicate that Cr prefers to reside in a U substitutional site and segregate to the grain boundary. The Bader charge analysis and the charge density difference analyses confirm that Cr forms bonds with neighboring O atoms that weaken the ionic nature of adjacent U-O bonds, especially when it occupies U substitutional site at the grain boundary. The implications of these findings for the usage of Cr2O3 as a growth promoter are discussed.
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U2 - 10.1016/j.commatsci.2013.05.008
DO - 10.1016/j.commatsci.2013.05.008
M3 - Article
AN - SCOPUS:84879123406
SN - 0927-0256
VL - 78
SP - 29
EP - 33
JO - Computational Materials Science
JF - Computational Materials Science
ER -