HR: 0830h
AN: T11C-0413    [PDF]
TI: Equation of State of (Mg$_{0.92}$, Fe$_{0.08}$)SiO$_{3}$ Perovskite from Shock Wave Study and its Geophysical Implications
AU: * Gong, Z
EM: z.gong@gl.ciw.edu
AF: Institute of Physics, Southwest Jiaotong University, No.111, North section,second circle rd,, Chengdu, 610031 China
AU: * Gong, Z
EM: z.gong@gl.ciw.edu
AF: Geophycical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd, MW, Washington, DC 20015 United States
AU: Dai, F
EM: dai@263.net
AF: Institute of Physics, Southwest Jiaotong University, No.111, North section,second circle rd,, Chengdu, 610031 China
AU: Fei, Y
EM: fei@gl.ciw.edu
AF: Geophycical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd, MW, Washington, DC 20015 United States
AU: Zhang, L
EM: miazl1980@hotmail.com
AF: Institute of Physics, Southwest Jiaotong University, No.111, North section,second circle rd,, Chengdu, 610031 China
AU: Jing, F
EM: jingfq@caep.ac.cn
AF: Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O.Box 919, Mianyang, 621900 China
AB: We performed shock wave experiments on (Mg$_{0.92}$, Fe$_{0.08}$)SiO$_{3}$enstatite with initial density of 3.06g/cm$^{3}$. 13 shock compression data points for (Mg$_{0.92}$, Fe$_{0.08}$)SiO$_{3}$perovskite were collected between 46 and 140 GPa, using impedance-match method and electrical probe technique. The relationship between shock wave velocity D and particle velocity u can been described linearly by D = 4.13 +1.39u(km/s). There is no evidence of phase transition in the experimental shock pressure range. Our experimental Hugoniot is about 7% denser than the model Hugoniot of (Mg$_{0.92}$, Fe$_{0.08}$)O (Mw.) plus SiO$_{2}$(St.) calculated by additive principle. This excludes the possibility of chemical decomposition of perovskite to oxides during the shock compression up to 140GPa. The Gr"1neisen parameter g obtained by fitting our experimental data can be expressed by $\gamma = \gamma_{0} (\rho_{0}\wedge \rho)^{q}$, where $\gamma_{0}$=1.40 and q=2.19. Using the third-order Birch-Murnaghan finite strain equation of state (EOS), our shock experimental data yield a zero-pressure bulk modulus K$_{0s}$=260.09 GPa and its pressure derivative K$_{0s}$=4.17, with $\rho_{0}=4.19$g/cm$^{3}$. A comparison of the calculated density profiles from our thermal equation of state of perovskite with that derived from PREM prefers a perovskite-dominant lower mantle model.
DE: 3919 Equations of state
DE: 3924 High-pressure behavior
DE: 3939 Physical thermodynamics
DE: 3944 Shock wave experiments
DE: 8124 Earth's interior--composition and state (old 8105)
SC: Tectonophysics [T]
MN: 2003 Fall Meeting