Electronic structure, magnetic properties, and mechanism of the insulator-metal transition in LaCoO{sub 3} taking into account strong electron correlations

Journal Article · Sat Jan 15 00:00:00 EST 2011 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776110061159· OSTI ID:22028185

Ovchinnikov, S G; Nekrasov, I A ^[1]; Pchelkina, Z V ^[2]

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1. Russian Academy of Sciences, Institute of Electrophysics, Ural Division (Russian Federation)
2. Russian Academy of Sciences, Institute of Metal Physics, Ural Division (Russian Federation)

The electronic structure of LaCoO{sub 3} at finite temperatures is calculated using the LDA+GTB method taking into account strong electron correlations and possible spin crossover upon an increase in temperature. Gap states revealed in the energy spectrum of LaCoO{sub 3} reduce the dielectric gap width upon heating; this allowed us to describe the insulator-metal transition observed in this compound at T = 500-600 K. The temperature dependence of the magnetic susceptibility with a peak at T Almost-Equal-To 100 K is explained by the Curie contribution from thermally excited energy levels of the Co{sup 3+} ion. At high temperatures, the Pauli contribution from a band electron is added and the total magnetization of LaCoO{sub 3} is considered as the sum M{sub tot} = M{sub loc} + M{sub band}. The second term describes the band contribution appearing as a result of the insulator-metal transition and facilitating the emergence of a high-temperature anomaly in the magnetic susceptibility of LaCoO{sub 3}.

• OSTI ID: 22028185
• Journal Information: Journal of Experimental and Theoretical Physics, Vol. 112, Issue 1; Other Information: Copyright (c) 2011 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
COBALT IONS
COBALT OXIDES
CURIE POINT
DIELECTRIC MATERIALS
ELECTRON CORRELATION
ELECTRONIC STRUCTURE
ELECTRONS
ENERGY LEVELS
ENERGY SPECTRA
HEATING
LANTHANUM COMPOUNDS
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
PHASE TRANSFORMATIONS
SPIN
TEMPERATURE DEPENDENCE