Variation of electronic structure in La 1-xSr xMnO 3 (0≤x≤0.3) as investigated by optical conductivity spectra

Y. Okimoto, Takuro Katsufuji, T. Ishikawa, T. Arima, Y. Tokura

Research output: Contribution to journalArticle

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Abstract

Optical conductivity spectra and their variation with temperature and doping level x have been investigated for single crystals of La 1-xSr xMnO 3 (0≤x≤0.3). For the low-doped insulating crystal (x = 0.1) which shows a ferromagnetic insulating state at low temperature, the spectral weight of the optical conductivity increases only in the inner-gap region around 0.5 eV, but no Drude part emerges due to carrier localization effect. For x≥0.17, where the low-temperature ferromagnetic metallic state shows up, the optical conductivity spectrum above T c is characterized by interband transitions between the exchange-split conduction bands, and it gradually changes into that of intraband excitations below T c. The energy scale (up to ≈ 2 eV) of the spectral weight transfer is determined by the effective Hund's-rule coupling energy. In the metallic phase, low-energy spectra arising from intraband excitations can be sorted into two parts: One is a nearly ω-independent broad structure (incoherent part), and the other a sharp coherent Drude peak with anomalously low spectral weight. This can hardly be reconciled with the simple double-exchange theory, but indicates that another degree of freedom (e.g., the orbital ordering and/or electron-lattice interactions) should be taken into account.

Original languageEnglish
Pages (from-to)4206-4214
Number of pages9
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume55
Issue number7
Publication statusPublished - 1997 Feb 15
Externally publishedYes

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Optical conductivity
Electronic structure
electronic structure
conductivity
Electron transitions
Conduction bands
Temperature
excitation
conduction bands
energy spectra
degrees of freedom
Doping (additives)
Single crystals
orbitals
Crystals
energy
Electrons
single crystals
crystals
electrons

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Variation of electronic structure in La 1-xSr xMnO 3 (0≤x≤0.3) as investigated by optical conductivity spectra. / Okimoto, Y.; Katsufuji, Takuro; Ishikawa, T.; Arima, T.; Tokura, Y.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 55, No. 7, 15.02.1997, p. 4206-4214.

Research output: Contribution to journalArticle

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