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A theoretical study of intrinsic point defects and defect clusters in magnesium aluminate spinel
journal contribution
posted on 2015-11-06, 15:14 authored by Christopher A. Gilbert, Roger Smith, Steven KennySteven Kenny, S.T. Murphy, R.W. Grimes, J.A. BallPoint and small cluster defects in magnesium aluminate spinel have been studied from a first principles viewpoint. Typical point defects that occur during collision cascade simulations are cation anti-site defects, which have a small formation energy and are very stable, O and Mg split interstitials and vacancies. Isolated Al interstitials were found to be energetically unfavourable
but could occur as part of a split Mg-Al pair or as a three atom-three vacancy Al ‘ring’ defect, previously observed in collision cascades using empirical potentials. The structure and energetics
of the defects were investigated using density functional theory (DFT) and the results compared to simulations using empirical fixed-charge potentials. Each point defect was studied in a variety of supercell sizes in order to ensure convergence. It was found that empirical potential simulations significantly overestimate formation energies, but that the type and relative stability of the defects are well-predicted by the empirical potentials both for point defects and small defect clusters.
History
School
- Science
Department
- Mathematical Sciences
Published in
JOURNAL OF PHYSICS-CONDENSED MATTERVolume
21Issue
27Pages
? - ? (7)Citation
GILBERT, C.A. ...et al., 2009. A theoretical study of intrinsic point defects and defect clusters in magnesium aluminate spinel. Journal of Physics-Condensed Matter, 21:275406.Publisher
© IOP PUBLISHING LTDVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
2009Notes
This article was published in the Journal of Physics: Condensed Matter [© IOP Publishing Ltd.] and the definitive version is available at: http://dx.doi.org/10.1088/0953-8984/21/27/275406ISSN
0953-8984Publisher version
Language
- en