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dc.contributor.authorSevincli, H.en_US
dc.contributor.authorSenger, R. T.en_US
dc.contributor.authorDurgun, E.en_US
dc.contributor.authorÇıracı, Salimen_US
dc.date.accessioned2016-02-08T10:14:11Z
dc.date.available2016-02-08T10:14:11Z
dc.date.issued2007en_US
dc.identifier.issn0953-8984
dc.identifier.urihttp://hdl.handle.net/11693/23456
dc.description.abstractRecently, first-principles calculations based on the spin-dependent density functional theory (DFT) have revealed that the magnetic ground state of a finite linear carbon chain capped by two transition metal (TM) atoms alternates between ferromagnetic and antiferromagnetic configurations depending on the number of carbon atoms. The character of indirect exchange coupling in this nanoscale, quasi-zero-dimensional system is different from those analogous extended structures consisting of magnetic layers separated by a non-magnetic spacer (or magnetic impurities in a non-magnetic host material) and a formulation based on an atomic picture is needed. We present a tight-binding model which provides a theoretical framework to the underlying mechanism of the exchange coupling in molecular structures. The model calculations are capable of reproducing the essential features of the DFT results for the indirect exchange coupling and the atomic magnetic moments in the TM-Cn-TM structures as functions of the number of carbon atoms. In nanostructures consisting of a few atoms the concepts of extended wavefunctions and the band theory lose their validity, and hence the oscillatory exchange coupling turns out to be a consequence of quantum interference effects due to the spin-dependent onsite and hopping energies. © IOP Publishing Ltd.en_US
dc.language.isoEnglishen_US
dc.source.titleJournal of Physics Condensed Matteren_US
dc.relation.isversionofhttp://dx.doi.org/10.1088/0953-8984/19/21/216205en_US
dc.subjectDensity functional theoryen_US
dc.subjectExchange couplingen_US
dc.subjectGround stateen_US
dc.subjectMagnetic momentsen_US
dc.subjectMolecular structureen_US
dc.subjectNanostructured materialsen_US
dc.subjectQuantum interference phenomenaen_US
dc.subjectCarbon chainen_US
dc.subjectFirst principles calculationsen_US
dc.subjectHopping energiesen_US
dc.subjectMagnetic layersen_US
dc.subjectMagnetic materialsen_US
dc.titleOscillatory exchange coupling in magnetic moleculesen_US
dc.typeArticleen_US
dc.departmentDepartment of Physicsen_US
dc.departmentInstitute of Materials Science and Nanotechnologyen_US
dc.citation.spage1en_US
dc.citation.epage13en_US
dc.citation.volumeNumber19en_US
dc.citation.issueNumber21en_US
dc.identifier.doi10.1088/0953-8984/19/21/216205en_US
dc.publisherIOP Publishingen_US
dc.contributor.bilkentauthorÇıracı, Salimen_US


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