TY - JOUR
T1 - Energetics of intrinsic point defects in uranium dioxide from electronic-structure calculations
AU - Nerikar, Pankaj
AU - Watanabe, Taku
AU - Tulenko, James S.
AU - Phillpot, Simon R.
AU - Sinnott, Susan B.
N1 - Funding Information:
We are happy to acknowledge support for this work through DOE-NERI Award DE-FC07-05ID14649 and the DOE-BES computational materials science network. We also thank the high performance computing (HPC) at the University of Florida for providing resources for the density functional theory calculations.
Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2009/1/31
Y1 - 2009/1/31
N2 - The stability range of intrinsic point defects in uranium dioxide is determined as a function of temperature, oxygen partial pressure, and non-stoichiometry. The computational approach integrates high accuracy ab initio electronic-structure calculations and thermodynamic analysis supported by experimental data. In particular, the density functional theory calculations are performed at the level of the spin polarized, generalized gradient approximation and includes the Hubbard U term; as a result they predict the correct anti-ferromagnetic insulating ground state of uranium oxide. The thermodynamic calculations enable the effects of system temperature and partial pressure of oxygen on defect formation energy to be determined. The predicted equilibrium properties and defect formation energies for neutral defect complexes match trends in the experimental literature quite well. In contrast, the predicted values for charged complexes are lower than the measured values. The calculations predict that the formation of oxygen interstitials becomes increasingly difficult as higher temperatures and reducing conditions are approached.
AB - The stability range of intrinsic point defects in uranium dioxide is determined as a function of temperature, oxygen partial pressure, and non-stoichiometry. The computational approach integrates high accuracy ab initio electronic-structure calculations and thermodynamic analysis supported by experimental data. In particular, the density functional theory calculations are performed at the level of the spin polarized, generalized gradient approximation and includes the Hubbard U term; as a result they predict the correct anti-ferromagnetic insulating ground state of uranium oxide. The thermodynamic calculations enable the effects of system temperature and partial pressure of oxygen on defect formation energy to be determined. The predicted equilibrium properties and defect formation energies for neutral defect complexes match trends in the experimental literature quite well. In contrast, the predicted values for charged complexes are lower than the measured values. The calculations predict that the formation of oxygen interstitials becomes increasingly difficult as higher temperatures and reducing conditions are approached.
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U2 - 10.1016/j.jnucmat.2008.10.003
DO - 10.1016/j.jnucmat.2008.10.003
M3 - Article
AN - SCOPUS:57849154055
SN - 0022-3115
VL - 384
SP - 61
EP - 69
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - 1
ER -