HR: 0800h
AN: MR31B-0363    [Abstracts]
TI: High-temperature compression of ferropericlase and effect of temperature on iron spin transition
AU: * Sugimura, E
EM: sugimura@geo.titech.ac.jp
AF: Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo, 152-8551, Japan
AU: Komabayashi, T
EM: komabayashi.t.aa@m.titech.ac.jp
AF: Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo, 152-8551, Japan
AU: Hirose, K
EM: kei@geo.titech.ac.jp
AF: Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo, 152-8551, Japan
AU: Hirose, K
EM: kei@geo.titech.ac.jp
AF: Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka, Kanagawa, 237-0061, Japan
AU: Sata, N
EM: sata@jamstec.go.jp
AF: Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka, Kanagawa, 237-0061, Japan
AU: Ohishi, Y
EM: ohishi@spring8.or.jp
AF: Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo, 679-5198, Japan
AU: Dubrovinsky, L S
EM: leonid.dubrovinsky@uni-bayreuth.de
AF: Bayerisches Geoinstitut, Universitaet Bayreuth, Bayreuth, D-, 95440, Germany
AB: High-temperature compression experiments of ferropericlase (Fp) with a composition of (Mg_0.81,Fe_0.19)O were operated in an externally-heated diamond anvil cell from 19 to 85 GPa at a constant temperature of 859-869 K at the beamline BL10XU, SPring-8. Room-temperature experiments with laser-annealing technique were also carried out on the same material. Anomalous volume reductions which cannot be explained by the normal compression behavior were observed at 60-82 GPa and 58-64 GPa at high temperature and room temperature, respectively. These volume reductions are likely to be related to the spin transition of ferrous iron in Fp. The spin transition pressure interval expands with increasing temperature. At the base of the mantle, in subducted cold slabs, Fp may have full low-spin iron while in hot upwelling plumes, Fp has relatively high-spin rich iron. This difference in the spin state will result in the density contrast at the core-mantle boundary. We will discuss the temperature dependence of the nature of the spin transition.
DE: 3630 Experimental mineralogy and petrology
DE: 3919 Equations of state
DE: 3924 High-pressure behavior
DE: 3954 X-ray, neutron, and electron spectroscopy and diffraction
SC: Mineral and Rock Physics [MR]
MN: 2007 Fall Meeting