Aug, 2004
High pressure and high temperature phase transitions of FeO
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
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- Volume
- 146
- Number
- 1-2
- First page
- 273
- Last page
- 282
- Language
- English
- Publishing type
- Research paper (scientific journal)
- DOI
- 10.1016/j.pepi.2003.06.011
- Publisher
- ELSEVIER SCIENCE BV
We investigated the phase transitions of FeO at high pressure and high temperature up to 87 GPa and 1730 K by in situ synchrotron X-ray diffraction measurements in a laser-heated diamond anvil cell (DAC). The results demonstrated that the NaCl-type (B1) structure of FeO undergoes transition to the NiAs-type (B8) structure above 70 GPa at 1600 K. The density increase across this transition is about 2%. Present B1-B8 transition pressure is consistent with the previous shock-induced transition pressure. The relative intensities of diffraction peaks of the B8 phase may suggest a polytype normal/inverse NiAs structure, which has a metallic nature that could promote the oxygen incorporation into the iron-rich core. Transition to the metallic B8 phase above 70 GPa is also consistent with the earlier electrical resistance measurements. The hexagonal close-packed (hcp) epsilon-phase of Fe coexisted with FeO both at room temperature and high temperatures above 44-87 GPa. (C) 2004 Elsevier B.V. All rights reserved.
- Link information
- ID information
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- DOI : 10.1016/j.pepi.2003.06.011
- ISSN : 0031-9201
- CiNii Articles ID : 80016815872
- Web of Science ID : WOS:000222979700020