Formation and migration of oxygen vacancies in La1−xSrxCo1−yFeyO3−δperovskites: insight from ab initio calculations and comparison with Ba1−xSrxCo1−yFeyO3−δ
- 1 January 2013
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Physical Chemistry Chemical Physics
- Vol. 15 (3), 911-918
- https://doi.org/10.1039/c2cp43557h
Abstract
The formation and migration of oxygen vacancies in the series of (La,Sr)(Co,Fe)O3−δ perovskites, which can be used as mixed conducting SOFC cathode materials and oxygen permeation membranes, are explored in detail by means of first principles density functional calculations. Structure distortions, charge redistributions and transition state energies during the oxygen ion migration are obtained and analyzed. Both the overall chemical composition and vacancy formation energy are found to have only a small impact on the migration barrier; it is rather the local cation configuration which affects the barrier. The electron charge transfer from the migrating O ion towards the transition metal ion in the transition state is much smaller in (La,Sr)(Co,Fe)O3−δ compared to (Ba,Sr)(Co,Fe)O3−δ perovskites where such a charge transfer makes a significant contribution to the low migration barriers observed (in particular for high Ba and Co content).Keywords
This publication has 48 references indexed in Scilit:
- Enhanced one dimensional mobility of oxygen on strained LaCoO3(001) surfaceJournal of Materials Chemistry, 2011
- First principles calculations of oxygen vacancy formation and migration in mixed conducting Ba0.5Sr0.5Co1−yFeyO3−δ perovskitesSolid State Ionics, 2011
- Structural Stability and Catalytic Activity of Lanthanum-Based PerovskitesThe Journal of Physical Chemistry C, 2011
- DFT investigation on SmCoO3-based mixed ionic-electronic conductorSolid State Sciences, 2011
- First-principles electronic-structure calculations on the stability and oxygen conductivity in Ba0.5Sr0.5Co0.8Fe0.2O3−δJournal of Membrane Science, 2011
- Understanding oxygen vacancy migration and clustering in barium strontiumcobalt iron oxideSolid State Ionics, 2010
- An atomistic simulation study of oxygen-vacancy migration in perovskite electrolytes based on LaGaO3Monatshefte für Chemie / Chemical Monthly, 2009
- Oxygen tracer diffusion in dense Ba0.5Sr0.5Co0.8Fe0.2O3−δ filmsApplied Physics Letters, 2009
- Phase equilibria and crystal structures of solid solutions in the system LaCoO3−δ-SrCoO2.5±δ-SrFeO3−δ-LaFeO3−δInorganic Materials, 2007
- On the enthalpic contribution to the redox energetics of SrFeO3–δPhysical Chemistry Chemical Physics, 2002