We have studied the “charge disproportionation” phenomenon in La1-xSrxFeO3 by photoemission spectroscopy and unrestricted Hartree-Fock band-structure calculations. We find a systematic decrease of the spectral intensity near Fermi level (EF) toward x=0.67, where the charge disproportion is most stabilized. The spectra for x=0.67 show the clearest temperature-dependent changes in the vicinity of EF across the transition corresponding to the charge ordering of “Fe3+”:“Fe5+”=2:1. The Hartree-Fock calculations indicate that ordering of oxygen holes indeed occurs in the charge disproportionated state.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 1999
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