HR: 0800h
AN: DI41A-0339    [Abstracts]
TI: The equation of state and structure stability of elemental metal vanadium under high pressure -from experiments to theories
AU: * Ding, Y
EM: yangding@aps.anl.gov
AF: HPSynC-Carnegie Institution of Washington, Building 401, 9700 South Cass Avenue, Argonne, IL 60637, United States
AU: Ahuja, R
EM: Rajeev.Ahuja@fysik.uu.se
AF: Department of Physics, Condensed Matter Theory Group, Box 530, Uppsala University, Uppsala, SE-751 21, Sweden
AU: Shu, J
EM: shu@gl.ciw.edu
AF: 3Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, United States
AU: Chow, P
EM: pchow@hpcat.aps.anl.gov
AF: 3Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, United States
AU: Luo, W
EM: wei.luo@fysik.uu.se
AF: Department of Physics, Condensed Matter Theory Group, Box 530, Uppsala University, Uppsala, SE-751 21, Sweden
AU: Mao, H
EM: h.mao@gl.ciw.edu
AF: 3Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, United States
AB: The EOS of elemental metal vanadium was measured using diamond anvil cell and synchrotron x-ray powder diffraction techniques up to 1.5 Mbar. A phase transition was observed at 63-69 GPa and room temperature in vanadium. The transition is characterized as a rhombohedral lattice distortion of the body-centered cubic vanadium without a discontinuity in the pressure-volume data, thus representing a novel type of transition that has never been observed in elements. The first principles calculations of electronic structure and lattice dynamics indicate that, instead of driven by the conventional s-d electronic transition mechanism, the phase transition is associated with the softening of C44 trigonal elasticity tensor that originates from the combination of Fermi surface nesting, band Jahn-Teller distortion and electronic topological transition. Major references related to this work, (1) Yang Ding et al , Structural Phase Transition of Vanadium at 69 GPa Phys. Rev. Lett. 98, 085502 (2007). (2)Wei Luo, Rajeev Ahuja, Yang Ding, and Ho-kwang Mao, "Unusual lattice dynamics of Vanadium under high pressure", submitted to PNAS. (3) Byeongchan Lee et al., "Theoretical confirmation of a high-pressure rhombohedral phase in vanadium metal", Phys. Rev. B 75, 180101 (R) (2007)
DE: 3611 Thermodynamics (0766, 1011, 8411)
DE: 3919 Equations of state
DE: 8147 Planetary interiors (5430, 5724, 6024)
SC: Study of the Earth's Deep Interior [DI]
MN: 2007 Fall Meeting