Skelton, R and Walker, AM orcid.org/0000-0003-3121-3255 (2017) Peierls-Nabarro modeling of dislocations in UO₂. Journal of Nuclear Materials, 495. pp. 202-210. ISSN 0022-3115
Abstract
Under conditions of high stress or low temperature, glide of dislocations plays an important role in the deformation of UO2. In this paper, the Peierls-Nabarro model is used to calculate the core widths and Peierls stresses of ½<110> edge and screw dislocations gliding on {100}, {110}, and {111}. The energy of the inelastic displacement field in the dislocation core is parameterized using generalized stacking fault energies, which are calculated atomistically using interatomic potentials. We use seven different interatomic potential models, representing the variety of different models available for UO2. The different models broadly agree on the relative order of the strengths of the different slip systems, with the 1/2<110>{100} edge dislocation predicted to be the weakest slip system and 1/2<110>{110} the strongest. However, the calculated Peierls stresses depend strongly on the interatomic potential used, with values ranging between 2.7 and 12.9 GPa for glide of 1/2<110>{100} edge dislocations, 16.4–32.3 GPa for 1/2<110>{110} edge dislocations, and 6.8–13.6 GPa for 1/2<110>{111} edge dislocations. The glide of 1/2<110> screw dislocations in UO2 is also found to depend on the interatomic potential used, with some models predicting similar Peierls stresses for glide on {100} and {111}, while others predict a unique easy glide direction. Comparison with previous fully atomistic calculations show that the Peierls-Nabarro model can accurately predict dislocation properties in UO2.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 Elsevier B.V. This is an author produced version of a paper published in Journal of Nuclear Materials. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Dislocation; Peierls-Nabarro modelling; UO2; Peierls stress |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Funding Information: | Funder Grant number NERC NE/K008803/1 NERC NE/M000044/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Aug 2017 09:13 |
Last Modified: | 17 Aug 2018 00:38 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.jnucmat.2017.08.024 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:120210 |