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A Model to Determine the Chemical Expansion in Non-Stoichiometric Oxides Based on the Elastic Force Dipole
- Source :
- Journal of the Electrochemical Society 161 (2014): F3060–F3064. doi:10.1149/2.0101411jes, info:cnr-pdr/source/autori:Er, D.; Li, J.; Cargnello, M.; Fornasiero, P.; Gorte, R. J.; Shenoy, V. B./titolo:A Model to Determine the Chemical Expansion in Non-Stoichiometric Oxides Based on the Elastic Force Dipole/doi:10.1149%2F2.0101411jes/rivista:Journal of the Electrochemical Society/anno:2014/pagina_da:F3060/pagina_a:F3064/intervallo_pagine:F3060–F3064/volume:161
- Publication Year :
- 2014
- Publisher :
- The Electrochemical Society, 2014.
-
Abstract
- In this work a novel continuum model informed by density functional theory (DFT) simulations is presented and used to predict the chemical expansion observed in non-stoichiometric oxides. We introduce an elastic dipole tensor that describes the long-range elastic fields created upon formation of oxygen vacancies. We show that this tensor, which can be accurately determined through first-principle DFT calculations, can be used to predict the chemical.expansion of ceria and in general other non-stoichiometric oxides. Compared to previous work where expansivity waS obtained with empirical potentials, our work provides an efficient way of computing it directly by DFT calculations. Furthermore, we discuss how the elastic dipole tensor can predict the O-2 partial pressure vs O/Ce ratios in strained systems and show that CeO2 can be reduced more easily in the presence of tensile strains. More generally, the elastic dipoles can be used in continuum models to predict the distribution of vacancies near nanocrystal surfaces, grain boundaries and extended defects such as dislocations and hence provide information on how these structures and defects influence the overall reducibility of the material. (C) 2014 The Electrochemical Society. All rights reserved.
- Subjects :
- Renewable Energy, Sustainability and the Environment
Chemistry
Condensed Matter Physics
DFT
DFT, ceria
ceria
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
Condensed Matter::Materials Science
Dipole
Computational chemistry
Chemical physics
calculations
Materials Chemistry
Electrochemistry
Elastic Force Dipole
Stoichiometry
Subjects
Details
- ISSN :
- 19457111 and 00134651
- Volume :
- 161
- Database :
- OpenAIRE
- Journal :
- Journal of The Electrochemical Society
- Accession number :
- edsair.doi.dedup.....c2d9ef6242a0373eb55c9c92981eb542