Adam P. Sorini

Publications (2)3.69 Total impact

• Source

  Available from: Yong Cai

  Article: High pressure evolution of Fe$_{2}$O$_{3}$ electronic structure revealed by X-ray absorption

  Shibing Wang, Wendy L Mao, Adam P. Sorini, Cheng-Chien Chen, Thomas P. Devereaux, Yang Ding, Yuming Xiao, Paul Chow, Nozomu Hiraoka, Hirofumi Ishii, Yong Q Cai, Chi-Chang Kao
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  ABSTRACT: We report the first high pressure measurement of the Fe K-edge in hematite (Fe$_2$O$_3$) by X-ray absorption spectroscopy in partial fluorescence yield geometry. The pressure-induced evolution of the electronic structure as Fe$_2$O$_3$ 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 phase transitions of Fe$_2$O$_3$ is discussed and it is shown that ligand hybridization significantly reduces the critical high-spin/low-spin gap pressure. Comment: 5 pages, 4 figures and 1 table
  06/2010;
• Source

  Available from: Yong Cai

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

  Shibing Wang, Wendy L. Mao, Adam P. Sorini, Cheng-Chien Chen, Thomas P. Devereaux, Yang Ding, Yuming Xiao, Paul Chow, Nozomu Hiraoka, Hirofumi Ishii, Yong Q. Cai, Chi-Chang Kao
  [show abstract] [hide abstract]
  ABSTRACT: 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.
  Physical Review B 01/2010; 82:144428. · 3.69 Impact Factor