Edge dislocation slows down oxide ion diffusion in doped CeO2 by segregation of charged defects
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Edge discoloration.pdf
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1.46 MB
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Author(s)
Sun, Lixin
Marrocchelli, Dario
Yildiz, Bilge
Date Issued
February 2015
Journal
Nature Communications
Publisher
Nature Publishing Group
Citation
Sun, Lixin; Marrocchelli, Dario and Yildiz, Bilge. “Edge Dislocation Slows down Oxide Ion Diffusion in Doped CeO2 by Segregation of Charged Defects.” Nature Communications 6 (February 27, 2015): 6294. © 2015 Macmillan Publishers Limited
Version
Final published version
Abstract
Strained oxide thin films are of interest for accelerating oxide ion conduction in electrochemical devices. Although the effect of elastic strain has been uncovered theoretically, the effect of dislocations on the diffusion kinetics in such strained oxides is yet unclear. Here we investigate a 1/2<110>{100} edge dislocation by performing atomistic simulations in 4–12% doped CeO₂ as a model fast ion conductor. At equilibrium, depending on the size of the dopant, trivalent cations and oxygen vacancies are found to simultaneously enrich or deplete either in the compressive or in the tensile strain fields around the dislocation. The associative interactions among the point defects in the enrichment zone and the lack of oxygen vacancies in the depletion zone slow down oxide ion transport. This finding is contrary to the fast diffusion of atoms along the dislocations in metals and should be considered when assessing the effects of strain on oxide ion conductivity.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
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Creative Commons Attribution 4.0 International License
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DOI of Published Version
https://doi.org/10.1038/ncomms7294
