Photoemission and Hartree-Fock studies of oxygen-hole ordering in charge-disproportionated La 1 − x Sr x FeO 3
Photoemission and Hartree-Fock studies of oxygen-hole ordering in charge-disproportionated La 1 − x Sr x FeO 3
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DOI：
10.1103/physrevb.60.4605
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发表时间：
1999-08
影响因子：
3.7
通讯作者：
J. Matsuno;T. Mizokawa;A. Fujimori;K. Mamiya;Y. Takeda;S. Kawasaki;M. Takano
中科院分区：
文献类型：
--
作者：
J. Matsuno;T. Mizokawa;A. Fujimori;K. Mamiya;Y. Takeda;S. Kawasaki;M. Takano
利用光谱学和无限制Hartree-Fock波段结构计算，研究了${\ mathm {La}} {{1\ensuremath{-}x}{\ mathm {Sr}} {{x}{\ mathm {FeO}}_{3}$中的“电荷歧化”现象。我们发现在费米能级${(E}_{F})$附近，光谱强度有系统地减小，趋于$x=0.67,$ x=0.67是电荷不成比例最稳定的地方。$x=0.67$的光谱显示了${E}_{F}$附近最明显的温度依赖变化，对应于$ '' ' {\mathrm{Fe}}^{3+} " $:$ '' ' {\mathrm{Fe}}^{5+} " \phantom{\rule{0ex}{0ex} =\phantom{\rule{0ex}{0ex}}的电荷顺序为2:1。Hartree-Fock计算表明，氧空穴的排序确实发生在电荷歧化态。
We have studied the ``charge disproportionation'' phenomenon in ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{FeO}}_{3}$ by photoemission spectroscopy and unrestricted Hartree-Fock band-structure calculations. We find a systematic decrease of the spectral intensity near Fermi level ${(E}_{F})$ 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 ${E}_{F}$ across the transition corresponding to the charge ordering of $``{\mathrm{Fe}}^{3+}''$:$``{\mathrm{Fe}}^{5+}''\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2:1.$ The Hartree-Fock calculations indicate that ordering of oxygen holes indeed occurs in the charge disproportionated state.