Journal Article

PreJuSER-12648

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Origin of Jahn-Teller distortion and orbital-order in LaMnO3

Pavarini, E.FZJ* ; Koch, E.FZJ*

2010
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/7262  doi:10.1103/PhysRevLett.104.086402

Abstract: The origin of the cooperative Jahn-Teller distortion and orbital order in LaMnO3 is central to the physics of the manganites. The question is complicated by the simultaneous presence of tetragonal and GdFeO3-type distortions and the strong Hund's rule coupling between e(g) and t(2g) electrons. To clarify the situation we calculate the transition temperature for the Kugel-Khomskii superexchange mechanism by using the local density approximation + dynamical mean-field method, and disentangle the effects of superexchange from those of lattice distortions. We find that superexchange alone would yield T-KK similar to 650 K. The tetragonal and GdFeO3-type distortions, however, reduce T-KK to similar to 550 K. Thus electron-phonon coupling is essential to explain the persistence of local Jahn-Teller distortions to greater than or similar to 1150 K and to reproduce the occupied orbital deduced from neutron scattering.

Keyword(s): J

Note: Record converted from VDB: 12.11.2012

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Contributing Institute(s):

1. Theorie der Strukturbildung (IFF-3)
2. Theoretische Nanoelektronik (IAS-3)
3. Jülich Aachen Research Alliance - High-Performance Computing (JARA-HPC)

Research Program(s):

1. Grundlagen für zukünftige Informationstechnologien (P42)

Appears in the scientific report 2010

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