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Author Olsson, Emilia ♦ Aparicio-Anglès, Xavier ♦ Leeuw, Nora H. de
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword 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
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 less energetically favorable than oxygen vacancies and would thus not markedly influence the performance of the cathode.
ISSN 00219606
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-07-07
Publisher Place United States
Journal Journal of Chemical Physics
Volume Number 145
Issue Number 1


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