HR: 11:50h
AN: MR22A-08    [Abstracts]
TI: Effect of alloying elements on the magnetic transitions in iron-rich alloys
AU: * Li, J
EM: jackieli@uiuc.edu
AF: University of Illinois, Department of Geology 1301 West Green Street 245 Natural History Building, urbana, IL 61801, United States
AU: Gao, L
EM: liligao2@uiuc.edu
AF: University of Illinois, Department of Geology 1301 West Green Street 245 Natural History Building, urbana, IL 61801, United States
AU: Chen, B
EM: binchen2@uiuc.edu
AF: University of Illinois, Department of Geology 1301 West Green Street 245 Natural History Building, urbana, IL 61801, United States
AU: Vescogni, H
EM: hrvescog@uiuc.edu
AF: University of Illinois, Department of Geology 1301 West Green Street 245 Natural History Building, urbana, IL 61801, United States
AU: Ding, X
EM: xding@gig.ac.cn
AF: University of Illinois, Department of Geology 1301 West Green Street 245 Natural History Building, urbana, IL 61801, United States
AU: Ding, Y
EM: yding@hpcat.aps.anl.gov
AF: Argonne National Laboratory, HPCAT, Bld. 434E Advanced Photon Source 9700 South Cass Ave, Lamont, IL 60439, United States
AU: Sinegeikin, S V
EM: ssinog@hpcat.aps.anl.gov
AF: Carnegie Institution of Washington, HPCAT and Geophysical Laboratory 5251 Broad Branch Rd, Washingtoon, DC 20015, United States
AU: Yang, W
EM: wyang@hpcat.aps.anl.gov
AF: Carnegie Institution of Washington, HPCAT and Geophysical Laboratory 5251 Broad Branch Rd, Washingtoon, DC 20015, United States
AU: Sturhahn, W
EM: sturhahn@anl.gov
AF: Argonne National Laboratory, Experimental Facilities Division Advanced Photon Source 9700 South Cass Ave, Lamont, IL 60439, United States
AB: Pressure induced spin-pairing transitions occur in iron-bearing alloys, oxides, and silicates and affect the physical properties and chemical behavior of the Earth???¨º?¨¨s deep interior. Compared with diluted systems such as lower mantle magnesian silicate perovskite and ferro-periclase, loss of magnetic moments in iron-rich core alloys occurs at much lower pressure, and may involve different mechanisms from high- to low-spin transition in iron. We have measured the compression curve of a natural cohenite sample up to 56 GPa, using diamond anvil cells and synchrotron x-ray diffraction techniques at HPCAT, Argonne National Laboratory. In this study, we examine existing x-ray emission spectroscopy, synchrotron M?ssbauer spectroscopy, and x-ray magnetic circular dichroism data in order to understand the effect of H, C, P, S, Si, and Ni on the nature of magnetic transitions in iron-rich alloys. Combined with new and existing nuclear resonant inelastic x-ray scattering and x-ray diffraction data, we investigate the systematic effect of magnetic transitions on the density and velocities of these alloys.
DE: 1015 Composition of the core
DE: 3919 Equations of state
DE: 3924 High-pressure behavior
DE: 3929 NMR, Mossbauer spectroscopy, and other magnetic techniques
DE: 3954 X-ray, neutron, and electron spectroscopy and diffraction
SC: Mineral and Rock Physics [MR]
MN: 2007 Fall Meeting