HR: 11:35h
AN: MR22A-06    [Abstracts]
TI: Strong chemistry dependence of the perovskite - post-perovskite phase transition boundary and of the post-perovskite structure
AU: * Tschauner, O
EM: olivert@physics.unlv.edu
AF: High Pressure Science and Engineering Center, Department of Physics, University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154 United States
AU: Somayazulu, M
EM: msomayazulu@hpcat.aps.anl.gov
AF: HPCAT, Advanced Photon Source, Argonne National Laboratory, Argonne National Laboratory 434-E002 9700 S. Cass Avenue, Chicago, IL 60439 United States
AU: Liu, H
EM: hliu@hpcat.aps.anl.gov
AF: HPCAT, Advanced Photon Source, Argonne National Laboratory, Argonne National Laboratory 434-E002 9700 S. Cass Avenue, Chicago, IL 60439 United States
AU: Luo, S
EM: sluo@lanl.gov
AF: Plasma Physics (P-24) and Earth and Environmental Sciences (EES-11), Los Alamos National Laboratory, Plasma Physics P-24, MS E526 Los Alamos National Laboratory , Los Alamos, NM 87545 United States
AB: We show that MgSiO3 of representative mantle composition transforms to the post-perovskite structure at a noticeable lower pressure than pure MgSiO3. We also show that there is a further transition to a different post-perovskite than previously reported. Together, they indicate that minor-element chemistry, in particular the presence of Al, is highly influential on structure and stability of post-perovskite phases and puts constrains on rock composition and temperature profile in the Earth's lowermost mantle. We further present the first Raman spectrum of a post-perovskite phase which indicates a strong polarized bonding between the Mg- and the silicate-sublattice.
DE: 3620 Crystal chemistry
DE: 3924 High-pressure behavior
DE: 1645 Solid Earth
SC: Mineral and Rock Physics [MR]
MN: 2004 AGU Fall Meeting