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dc.contributor.authorNanda, B. R. K.eng
dc.contributor.authorSatpathy, Sashi Sekhar, 1956-eng
dc.date.issued2008eng
dc.description.abstractWe study how strain affects orbital ordering and magnetism at the interface between SrMnO3 and LaMnO3 from density-functional calculations and interpret the basic results in terms of a three-site Mn-O-Mn model. Magnetic interaction between the Mn atoms is governed by a competition between the antiferromagnetic superexchange of the Mn t2g core spins and the ferromagnetic double exchange of the itinerant eg electrons. While the core electrons are relatively unaffected by the strain, the orbital character of the itinerant electron is strongly affected, which in turn causes a large change in the strength of the ferromagnetic double exchange. The epitaxial strain produces the tetragonal distortion of the MnO6 octahedron, splitting the Mn eg states into x2−y2 and 3z2−1 states, with the former being lower in energy, if the strain is tensile in the plane and opposite if the strain is compressive. For the case of the tensile strain, the resulting higher occupancy of the x2−y2 orbital enhances the in-plane ferromagnetic double exchange owing to the larger electron hopping in the plane, causing at the same time a reduction in the out-of-plane double exchange. This reduction is large enough to be overcome by antiferromagnetic superexchange, which wins to produce a net antiferromagnetic interaction between the out-of-plane Mn atoms. For the case of the in-plane compressive strain, the reverse happens, viz., that the higher occupancy of the 3z2−1 orbital results in the out-of-plane ferromagnetic interaction, while the in-plane magnetic interaction remains antiferromagnetic. Concrete density-functional results are presented for the (LaMnO3)1/(SrMnO3)1 and (LaMnO3)1/ (SrMnO3)3 superlattices for various strain conditions.eng
dc.description.sponsorshipThis work was supported by the U.S. Department of Energy under Grant No. DE-FG02-00ER45818.eng
dc.identifier.citationPhys. Rev. B 78, 054427 (2008) [12 pages]eng
dc.identifier.urihttp://hdl.handle.net/10355/7227eng
dc.languageEnglisheng
dc.publisherAmerican Physical Societyeng
dc.relation.ispartofcollectionUniversity of Missouri--Columbia. College of Arts and Sciences. Department of Physics and Astronomy. Physics and Astronomy publicationseng
dc.source.urihttp://link.aps.org/doi/10.1103/PhysRevB.78.054427eng
dc.subjectmagnetic properties of interfaceseng
dc.subjectelectron density of states and band structure of crystalline solidseng
dc.subjectelectron states at surfaces and interfaceseng
dc.subjectlevel splitting and interactionseng
dc.subject.lcshAntiferromagnetismeng
dc.subject.lcshPerovskiteeng
dc.titleEffects of strain on orbital ordering and magnetism at perovskite oxide interfaces: LaMnO3/SrMnO3eng
dc.typeArticleeng


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