HR: 1340h
AN: MR23A-0193    [Abstracts]
TI: MgO: \textit{ab initio} equation of state and its dislocation properties from molecular dynamics simulations*
AU: Swift, D
AF: Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545 United States
AU: * Luo, S
EM: sluo@lanl.gov
AF: Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545 United States
AU: Strachan, A
AF: Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 United States
AU: Huang, H
AF: Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125 United States
AU: Mulford, R
AF: NMT Division, Los Alamos National Laboratory, Los Alamos, NM 87545
AU: Drummond, N
AF: Department of Physics and Astronomy, University of Edinburg, Edinburg, EH9 3JZ United Kingdom
AU: Ackland, G
AF: Department of Physics and Astronomy, University of Edinburg, Edinburg, EH9 3JZ United Kingdom
AU: Goddard, W
AF: Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125 United States
AB: The equation of state (EOS) of MgO, and its dislocation properties were investigated using {\it ab initio} quantum-mechanics techniques and classical molecular dynamics (MD) with a Morse-stretch charge-equilibrium potential, respectively. The thermodynamically complete {\it ab initio} EOS was demonstrated to be consistent with the isotherm, thermal expansivity, heat capacity and melting curve measured in static experiments, and reproduced density and temperature measurements under shock wave loading of bulk and porous periclase. The melting locus of MgO, relevant to the Earth's lower mantle pressures, was predicted to be accessible by shock wave loading of porous periclase. Preliminary MD simulations of dislocations in MgO indicated qualitative similarity to measurements of the temperature--stress curve, and revealed a qualitative understanding of the mechanism behind non-conservative motion of edge dislocations in MgO. *Work partly performed under the auspices of the US Department of Energy under contract No. W-7405-ENG-36.
DE: 3909 Elasticity and anelasticity
DE: 3919 Equations of state
DE: 3924 High-pressure behavior
DE: 3944 Shock wave experiments
SC: Mineral and Rock Physics [MR]
MN: 2004 AGU Fall Meeting