HR: 13:55h
AN: MR53A-02    [Abstracts]
TI: Compressibility and phase transition studies for amorphous materials under high pressure: Approach combined of synchrotron high energy x-ray diffraction and micro tomography techniques using diamond anvil cell
AU: Liu, H
AF: Harbin Institute of Technology, Research Academy of Science and Technology, P.O. Box 3025, Science Park, Harbin, 150080, China
AU: * Wang, L
AF: Harbin Institute of Technology, Research Academy of Science and Technology, P.O. Box 3025, Science Park, Harbin, 150080, China
AU: Xiao, X
AF: Argonne National Laboratory, Advanced Photon Source, Argonne, IL 60439, United States
AU: Lee, P
AF: Argonne National Laboratory, Advanced Photon Source, Argonne, IL 60439, United States
AU: Hemley, R
AF: Carnegie Institution of Washington, Geophysical Laboratory, Washington, DC, DC 20015, United States
AU: Mao, H
AF: Carnegie Institution of Washington, Geophysical Laboratory, Washington, DC, DC 20015, United States
AB: The structural evolution of amorphous materials under high pressure conditions is a virgin field that has not been extensively explored. Investigations by reaching large Q range using synchrotron high energy x-ray diffraction and diamond anvil cell (DAC) techniques were performed. The study of polyamorphism will undoubtedly broaden our horizons and perspectives of the states of matter in general, and may have a significant impact on the existing theories about the structure, formation, and evolution of amorphous materials. The procedure of the pressure- induced amorphous state to crystalline state is another interesting subject. Combine the high energy x-ray diffraction with the time resolved area detector, we not only could accurately measure the structural factors evolution of amorphous materials under pressure, but also could record the time dependence of the crystallization procedure. These will provide new insight on the nature of crystallization, provide new invitation for the electronic theoretical studies for the phase stability and competition in time and spatial domains, and improve our understanding of the kinetic process of the common pressure induced crystallization. Another technical development effort is the micro tomography study using DAC at radial geometrical setting. Although the two-dimensional imaging, i. e. x-ray radiography, is used in routine way for high pressure DAC experiments, the ˇ®volume imaging', i. e. x-ray tomography, will offer us more information regarding direct volume measurement, relative density measurement, and shear deformation under high pressure. The application in high pressure conditions by using DAC will greatly push our understanding of deformation mechanism down to lower mantle conditions. Another major application for DAC tomography will be the relative density measurement for the amorphous materials, metallic glasses, and liquid or melt in DAC under pressure, which will provide better information for the density of non-crystalline materials under pressure than the routine x- ray radiography. We will demonstrate the preliminary studies on DAC tomography for amorphous selenium, zinc oxide, gold and nickel polycrystal samples under pressure.
DE: 3620 Mineral and crystal chemistry (1042)
DE: 3924 High-pressure behavior
DE: 3954 X-ray, neutron, and electron spectroscopy and diffraction
DE: 3994 Instruments and techniques
SC: Mineral and Rock Physics [MR]
MN: 2007 Fall Meeting