Electronic structure, magnetic properties, and mechanism of the insulator-metal transition in LaCoO3 taking into account strong electron correlations

Описание

Тип публикации: статья из журнала

Год издания: 2011

Идентификатор DOI: 10.1134/S1063776110061159

Ключевые слова: Energy spectra, Excited energy level, Finite temperatures, Gap state, Gap widths, High temperature, High-temperature anomalies, Insulator metal transition, Pauli contribution, Spin crossovers, Strong electron correlations, Temperature dependence, Total magnetization, Cobalt compounds, Density functional theory, Electron correlations, Electron density measurement, Electronic properties, Electronic structure, Magnetic susceptibility, Semiconductor insulator boundaries, Spectroscopy, Metal insulator transition

Аннотация: The electronic structure of LaCoO3 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 LaCoO3 reduce the dielectric gap width upon heating; this allowed us to describeПоказать полностьюthe insulator-metal transition observed in this compound at T = 500-600 K. The temperature dependence of the magnetic susceptibility with a peak at T a parts per thousand 100 K is explained by the Curie contribution from thermally excited energy levels of the Co3+ ion. At high temperatures, the Pauli contribution from a band electron is added and the total magnetization of LaCoO3 is considered as the sum M (tot) = M (loc) + M (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 LaCoO3.

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Издание

Журнал: JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS

Выпуск журнала: Vol. 112, Is. 1

Номера страниц: 140-151

ISSN журнала: 10637761

Место издания: NEW YORK

Издатель: MAIK NAUKA/INTERPERIODICA/SPRINGER

Авторы

  • Ovchinnikov S.G. (Siberian Aerospace University)
  • Orlov Y.S. (Kirenskii Institute of Physics,Siberian Branch,Russian Academy of Sciences)
  • Nekrasov I.A. (Institute of Electrophysics,Ural Division,Russian Academy of Sciences)
  • Pchelkina Z.V. (Institute of Metal Physics,Ural Division,Russian Academy of Sciences)

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