HR: 0830h
AN: T11C-0410    [PDF]
TI: Inelastic x-ray scattering in extreme conditions: a tool for investigating deep planetary interiors.
AU: * Occelli, F
EM: occelli1@llnl.gov
AF: Lawrence Livermore National Laboratory - Energy \& Environment, 7000 East Avenue, Livermore, CA 94550 United States
AU: Badro, J
EM: james.badro@ens-lyon.fr
AF: Laboratoire de Min\'eralogie-Cristallographie, Universit\'e Paris VI - Institut de Physique du Globe de Paris, 4 place Jussieu, Paris Cedex 05, 75252 France
AU: Fiquet, G
EM: Guillaume.Fiquet@lmcp.jussieu.fr
AF: Laboratoire de Min\'eralogie-Cristallographie, Universit\'e Paris VI - Institut de Physique du Globe de Paris, 4 place Jussieu, Paris Cedex 05, 75252 France
AU: Farber, D L
EM: farber2@llnl.gov
AF: Lawrence Livermore National Laboratory - Energy \& Environment, 7000 East Avenue, Livermore, CA 94550 United States
AU: Guyot, F
EM: guyot@lmcp.jussieu.fr
AF: Laboratoire de Min\'eralogie-Cristallographie, Universit\'e Paris VI - Institut de Physique du Globe de Paris, 4 place Jussieu, Paris Cedex 05, 75252 France
AU: Gregoryanz, E
EM: e.gregoryanz@gl.ciw.edu
AF: Laboratoire de Min\'eralogie-Cristallographie, Universit\'e Paris VI - Institut de Physique du Globe de Paris, 4 place Jussieu, Paris Cedex 05, 75252 France
AU: Krisch, M
EM: krisch@esrf.fr
AF: European Synchrotron Radiation Facility, BP 220, Grenoble Cedex, 38043 France
AU: Requardt, H
EM: requardt@esrf.fr
AF: European Synchrotron Radiation Facility, BP 220, Grenoble Cedex, 38043 France
AU: Mermet, A
EM: mermet@pcml.univ-lyon1.fr
AF: European Synchrotron Radiation Facility, BP 220, Grenoble Cedex, 38043 France
AU: D'Astuto, M
EM: matteo.dastuto@pmc.jussieu.fr
AF: European Synchrotron Radiation Facility, BP 220, Grenoble Cedex, 38043 France
AB: To address the structure and composition of planetary interiors, and to confront mineralogical models with geophysical ({\it i.e.} seismological) observations, it is essential to measure the effects of pressure on the elastic properties of geo-materials. To date, many techniques have been employed for that purpose, such as ultrasonic techniques, inelastic neutron scattering, high-pressure Brillouin scattering, nuclear resonant inelastic scattering, radial x-ray diffraction, inelastic x-ray scattering (IXS), or more recently, impulse stimulated light scattering. Among all these techniques, only IXS in conjunction with the diamond anvil cell provides a direct measurement of acoustic (collective) excitations across the Brillouin zone to pressures in excess of 100\,GPa [{\it Fiquet et al.,} 2001] and with accuracies better than a few percent on any material (transparent, opaque, powder, single-crystal, etc\ldots). Such measurements allow a simple and direct derivation of sound velocities and elastic moduli that are model independent. We will present an overview of several IXS experiments on Fe and FeO at high pressure and on FeS at high pressure and temperature. These experiments were performed on poly-crystalline samples at the IXS-dedicated beamline ID28 of the European Synchrotron Radiation Facility. We will conclude by presenting results of IXS experiments performed on oriented single crystals that provide direct determinations of the phonon dispersion curves of molybdenum along its high symmetry crystallographic direction up to 37\,GPa. \\ \noindent G. Fiquet, J. Badro, F. Guyot, H. Requardt, and M. Krisch, Science \textbf{291}, 468 (2001).
DE: 3909 Elasticity and anelasticity
DE: 3924 High-pressure behavior
DE: 3954 X ray, neutron, and electron spectroscopy and diffraction
DE: 3994 Instruments and techniques
SC: Tectonophysics [T]
MN: 2003 Fall Meeting