High-pressure evolution of Fe2O3 electronic structure revealed by x-ray absorption

Article

关键词: EDGE STRUCTURE;    PRE-EDGE;    TRANSITION;    SCATTERING;    SPECTRA;    OXIDATION;    MAGNETISM;    COLLAPSE;    STATE;    FE;   

DOI  :  10.1103/PhysRevB.82.144428

来源: SCIE

【 摘 要 】

We report the high-pressure measurement of the Fe K edge in hematite (Fe2O3) by x-ray absorption spectroscopy in partial fluorescence yield geometry. The pressure-induced evolution of the electronic structure as Fe2O3 transforms from a high-spin insulator to a low-spin metal is reflected in the x-ray absorption pre-edge. The crystal-field splitting energy was found to increase monotonically with pressure up to 48 GPa, above which a series of phase transitions occur. Atomic multiplet, cluster diagonalization, and density-functional calculations were performed to simulate the pre-edge absorption spectra, showing good qualitative agreement with the measurements. The mechanism for the pressure-induced electronic phase transitions of Fe2O3 is discussed and it is shown that ligand hybridization significantly reduces the critical high-spin/low-spin transition pressure.

【 授权许可】

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