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Title: Ab initio study of vacancy formation in cubic LaMnO{sub 3} and SmCoO{sub 3} as cathode materials in solid oxide fuel cells

Abstract

Doped LaMnO{sub 3} and SmCoO{sub 3} are important solid oxide fuel cell cathode materials. The main difference between these two perovskites is that SmCoO{sub 3} has proven to be a more efficient cathode material than LaMnO{sub 3} at lower temperatures. In order to explain the difference in efficiency, we need to gain insight into the materials’ properties at the atomic level. However, while LaMnO{sub 3} has been widely studied, ab initio studies on SmCoO{sub 3} are rare. Hence, in this paper, we perform a comparative DFT + U study of the structural, electronic, and magnetic properties of these two perovskites. To that end, we first determined a suitable Hubbard parameter for the Co d–electrons to obtain a proper description of SmCoO{sub 3} that fully agrees with the available experimental data. We next evaluated the impact of oxygen and cation vacancies on the geometry, electronic, and magnetic properties. Oxygen vacancies strongly alter the electronic and magnetic structures of SmCoO{sub 3}, but barely affect LaMnO{sub 3}. However, due to their high formation energy, their concentrations in the material are very low and need to be induced by doping. Studying the cation vacancy concentration showed that the formation of cation vacancies is lessmore » energetically favorable than oxygen vacancies and would thus not markedly influence the performance of the cathode.« less

Authors:
;  [1];  [1]
  1. Department of Chemistry, University College London, London WC1H 0AJ (United Kingdom)
Publication Date:
OSTI Identifier:
22675917
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 145; Journal Issue: 1; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CATHODES; CATIONS; DOPED MATERIALS; EXPERIMENTAL DATA; FORMATION HEAT; LANTHANUM COMPOUNDS; MAGNETIC PROPERTIES; MANGANATES; OXYGEN; PEROVSKITES; SOLID FUELS; SOLID OXIDE FUEL CELLS; VACANCIES

Citation Formats

Olsson, Emilia, Aparicio-Anglès, Xavier, Leeuw, Nora H. de,, and School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT. Ab initio study of vacancy formation in cubic LaMnO{sub 3} and SmCoO{sub 3} as cathode materials in solid oxide fuel cells. United States: N. p., 2016. Web. doi:10.1063/1.4954939.
Olsson, Emilia, Aparicio-Anglès, Xavier, Leeuw, Nora H. de,, & School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT. Ab initio study of vacancy formation in cubic LaMnO{sub 3} and SmCoO{sub 3} as cathode materials in solid oxide fuel cells. United States. doi:10.1063/1.4954939.
Olsson, Emilia, Aparicio-Anglès, Xavier, Leeuw, Nora H. de,, and School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT. Thu . "Ab initio study of vacancy formation in cubic LaMnO{sub 3} and SmCoO{sub 3} as cathode materials in solid oxide fuel cells". United States. doi:10.1063/1.4954939.
@article{osti_22675917,
title = {Ab initio study of vacancy formation in cubic LaMnO{sub 3} and SmCoO{sub 3} as cathode materials in solid oxide fuel cells},
author = {Olsson, Emilia and Aparicio-Anglès, Xavier and Leeuw, Nora H. de, and School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT},
abstractNote = {Doped LaMnO{sub 3} and SmCoO{sub 3} are important solid oxide fuel cell cathode materials. The main difference between these two perovskites is that SmCoO{sub 3} has proven to be a more efficient cathode material than LaMnO{sub 3} at lower temperatures. In order to explain the difference in efficiency, we need to gain insight into the materials’ properties at the atomic level. However, while LaMnO{sub 3} has been widely studied, ab initio studies on SmCoO{sub 3} are rare. Hence, in this paper, we perform a comparative DFT + U study of the structural, electronic, and magnetic properties of these two perovskites. To that end, we first determined a suitable Hubbard parameter for the Co d–electrons to obtain a proper description of SmCoO{sub 3} that fully agrees with the available experimental data. We next evaluated the impact of oxygen and cation vacancies on the geometry, electronic, and magnetic properties. Oxygen vacancies strongly alter the electronic and magnetic structures of SmCoO{sub 3}, but barely affect LaMnO{sub 3}. However, due to their high formation energy, their concentrations in the material are very low and need to be induced by doping. Studying the cation vacancy concentration showed that the formation of cation vacancies is less energetically favorable than oxygen vacancies and would thus not markedly influence the performance of the cathode.},
doi = {10.1063/1.4954939},
journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 1,
volume = 145,
place = {United States},
year = {2016},
month = {7}
}