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

Academic Article

Abstract

  • We report the high-pressure measurement of the FeK 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. © 2010 The American Physical Society.
  • Digital Object Identifier (doi)

    Author List

  • Wang S; Mao WL; Sorini AP; Chen CC; Devereaux TP; Ding Y; Xiao Y; Chow P; Hiraoka N; Ishii H
  • Volume

  • 82
  • Issue

  • 14