Phonon density of states of Fe(2)O(3) across high-pressure structural and electronic transitions.
- X-Ray Science Division
High-pressure phonon density of states (PDOS) of Fe{sub 2}O{sub 3} across structural and electronic transitions has been investigated by nuclear resonant inelastic x-ray scattering (NRIXS) and first-principles calculations together with synchrotron Moessbauer, x-ray diffraction, and x-ray emission spectroscopies. Drastic changes in elastic, thermodynamic, and vibrational properties of Fe{sub 2}O{sub 3} occur across the Rh{sub 2}O{sub 3}(II)-type structural transition at 40-50 GPa, whereas the Mott insulator-metal transition occurring after the structural transition only causes nominal changes in the properties of the Fe{sub 2}O{sub 3}. The observed anomalous mode-softening behavior of the elastic constants is associated with the structural transition at 40-50 GPa, leading to substantial changes in the Debye-like part of the PDOS in the terahertz acoustic phonons. Our experimental and theoretical studies provide new insights into the effects of the structural and electronic transitions in the transition-metal oxide (TMO) compounds.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 1025717
- Report Number(s):
- ANL/XSD/JA-70841; TRN: US1104968
- Journal Information:
- Phys. Rev. B, Vol. 84, Issue Aug. 24, 2011; ISSN 1098--0121
- Country of Publication:
- United States
- Language:
- ENGLISH
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