HR: 08:30h
AN: V41B-03    [PDF]
TI: High-pressure and High-temperature Studies With Nuclear Resonant Scattering
AU: * Sturhahn, W
EM: sturhahn@anl.gov
AF: Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Ave, Argonne, IL 60439 United States
AU: Lin, J
AF: Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd, Washington, DC 20015 United States
AU: Zhao, J
AF: Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Ave, Argonne, IL 60439 United States
AU: Shen, G
AF: Consortium for Advanced Radiation Sources, University of Chicago, 5801 South Ellis Ave, Chicago, IL 60637 United States
AU: Prakapenka, V
AF: Consortium for Advanced Radiation Sources, University of Chicago, 5801 South Ellis Ave, Chicago, IL 60637 United States
AU: Mao, H
AF: Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd, Washington, DC 20015 United States
AB: In this contribution, we report the extention of nuclear resonant scattering techniques into the high-pressure and high-temperature sector relevant to the geophysical problem area. Nuclear resonant scattering techniques that utilize synchrotron radiation have provided new opportunities for the study of vibrational properties, magnetic properties, and iron valancies of condensed matter under extreme conditions. Here we will address nuclear resonant inelastic x-ray scattering (NRIXS), a method that uses probe nuclei with suitable resonances to measure the vibrational density of states, and synchrotron M\"ossbauer spectroscopy (SMS) for determination of valancies. Both methods are very sensitive to small amounts of material and take advantage of the high brilliance of synchrotron radiation, which makes micrometer-sized x-ray beams with high intensity possible. These properties allowed NRIXS and SMS investigations on materials under pressures in the Mbar regime using diamond anvil cells [1,2]. In general, NRIXS provides the phonon density of states [3] and sound velocities [4], whereas SMS gives access to the abundance of ferric iron in lower mantle polymorphs [2]. The introduction of Laser heating in combination with NRIXS and SMS at sector 3-ID of the Advanced Photon Source permits us now to conduct these studies under high pressure \textit{and} high temperature. First results on iron metal and iron-containing perovskite Fe$_{0.1}$Mg$_{0.9}$SiO$_3$ up to 50\,GPa and 1500\,K will be presented to exemplify the usefulness of these novel techniques. This work is supported by the U.S. DOE-BES, Office of Science, under Contract No. W-31-109-Eng-38. {}[1] H.K.Mao, J.Xu, V.V.Struzhkin, J.Shu, R.J.Hemley, W.Sturhahn, M.Y.Hu, E.E.Alp, L.Vocadlo, D.Alfe, G.D.Price, M.J.Gillan, M.Schwoerer-B\"ohning, D.H\"ausermann, P.Eng, G.Shen, H.Giefers, R.L\"ubbers, G.Wortmann, Science \textbf{292}, 914 (2001) {}[2] J.M.Jackson, W.Sturhahn, G.Shen, J.D.Bass, (unpublished) {}[3] W.Sturhahn, T.S.Toellner, E.E.Alp, X.Zhang, M.Ando, Y.Yoda, S.Kikuta, M.Seto, C.W.Kimball, and B.Dabrowski, Phys.Rev.Lett. \textbf{79}, 3832 (1995) {}[4] M.Y.Hu, W.Sturhahn, T.S.Toellner, P.Mannheim, E.E.Alp, Phys.Rev. B \textbf{67}, 094304 (2003)
DE: 3909 Elasticity and anelasticity
DE: 3924 High-pressure behavior
DE: 3929 NMR, Mossbauer spectroscopy, and other magnetic techniques
DE: 3954 X ray, neutron, and electron spectroscopy and diffraction
DE: 3994 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting