Correlation effects and energetics of point defects in uranium dioxide: a first principle investigation

Gupta, Florence; Brillant, G.; Pasturel, A.

doi:10.1080/14786430701235814

Cited by 103 publications

(112 citation statements)

References 26 publications

(26 reference statements)

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“…A somewhat better agreement is observed within the generalized gradient approximation 26 , i.e. GGA+U 10,[27][28][29] . Note that following Dudarev's calculations, we 55 employed recently the same values of U and J in our study on bulk properties and defects behaviour in UO 2 10 .…”

Section: Computational Detailsmentioning

confidence: 88%

Density functional theory calculations on magnetic properties of actinide compounds

Gryaznov

Heifets

Sedmidubský

2010

Phys. Chem. Chem. Phys.

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We have performed a detailed analysis of the magnetic (collinear and noncollinear) order and atomic and the electron structures of UO 2 , PuO 2 and UN on the basis of density functional theory with the Hubbard electron correlation correction (DFT+U). We have shown that the 3-k magnetic structure of UO 2 is the lowest in energy for the Hubbard parameter value of U=4.6 eV (and J=0.5 10 eV) consistent with experiments when Dudarev's formalism is used. In contrast to UO 2 , UN and PuO 2 show no trend for a distortion towards rhombohedral structure and, thus, no complex 3-k magnetic structure is to be anticipated in these materials.

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Section: Computational Detailsmentioning

confidence: 88%

Density functional theory calculations on magnetic properties of actinide compounds

Gryaznov

Heifets

Sedmidubský

2010

Phys. Chem. Chem. Phys.

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“…In order to simplify the calculation of defect properties the latter two contributions are ignored in the present study. Recent reports have shown that the LDA/GGA+U methodology correctly describes many of the relevant properties of UO 2 and UO 2+x 42,[44][45][46][47][48][49][50][51][52][53][54][55][56] . In accordance with earlier LDA+U studies the U and J values were set to U = 4.5 eV and J = 0.51 eV 46 .…”

Section: Approachmentioning

confidence: 99%

U and Xe transport in UO2±x: Density functional theory calculations

et al. 2011

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The detrimental effects of the fission gas Xe on the performance of oxide nuclear fuels are well known. However, less well known are the mechanisms that govern fission gas evolution. Here, in order to better understand bulk Xe behavior (diffusion mechanisms) in UO2±x we calculate the relevant activation energies using density functional theory (DFT) techniques. By analyzing a combination of Xe solution thermodynamics, migration barriers and the interaction of dissolved Xe atoms with U, we demonstrate that Xe diffusion predominantly occurs via a vacancy-mediated mechanism. Since Xe transport is closely related to diffusion of U vacancies, we have also studied the activation energy for this process. In order to best reproduce experimental data for the Xe and U activation energies, it is critical to consider the active charge-compensation mechanism for intrinsic defects in UO2±x. Due to the high thermodynamic cost of reducing U 4+ ions, any defect formation occurring at a fixed composition, i.e. no change in UO2±x stoichiometry, always avoids such reactions, which, for example, implies that the ground-state configuration of an O Frenkel pair in UO2 does not involve any explicit local reduction (oxidation) of U ions at the O vacancy (interstitial).

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“…Various actinide compounds, including UC and U-Pu-C alloys, have also recently been investigated as candidate fuels for next-generation reactors. 20,21 The intricate nature of the 5 f electrons in the actinides is crucial to understanding nuclear fuel properties such as chemical bonding, heat conductivity, 22 fi ssion gas behavior, 11,12,[14][15][16][17][18][19] and the surface interaction with molecules 23 relevant to fuel corrosion. 24 Hence, understanding actinide electronic structure is a prerequisite for understanding the behavior of nuclear fuel materials.…”

Section: Introductionmentioning

confidence: 99%

“…In fact, fi rstprinciples studies based on density functional theory (DFT) have already greatly contributed by supplying fundamental electronic-structure knowledge [1][2][3][4][5][6][7][8] and the material properties of defect-containing nuclear fuels. [9][10][11][12][13][14][15][16][17][18][19][20] Among all fuel materials, UO 2 and PuO 2 have been most extensively studied both experimentally and computationally. This is especially true for UO 2 , the standard nuclear fuel for light water reactors.…”

Section: Introductionmentioning

confidence: 99%