Berlin 2012 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 25: Focussed session: Frontiers of electronic structure theory: Strong correlations from first principles II (jointly with TT)
O 25.6: Vortrag
Dienstag, 27. März 2012, 12:00–12:15, HE 101
The magnetism in LaCoO3 from the perspective of the dynamical mean field theory. — •Vlastimil Křápek and Jan Kuneš — Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 16253 Praha 6, Czech Republic
Despite numerous studies the character of the high-temperature magnetism in insulating LaCoO3 is still controversial. Two candidates for the origin of the high-temperature Curie-Weiss response have been considered in literature: the intermediate spin state (IS, S=1) [1] and the high spin state (HS, S=2) [2]. We use the dynamical mean field approximation combined with the local density approximation (LDA+DMFT) to study LaCoO3. We discuss the meaning of IS and HS states in the presence of change fluctuations due to the covalency Co-O bonds and conclude that HS is the dominant magnetic state for all realistic interaction parameters.
[1] M. A. Korotin et al., Phys. Rev. B 54, 5309 (1996).
[2] P. M. Raccah and J. B. Goodenough, Phys. Rev. 155, 932 (1967).