Molecular Dynamics Simulation of MgSiO3 Perovskite
ZHOU Lin-xiang1, J. R. Hardy2, XU Xin3
1Department of Physics, Xiamen University, Xiamen 361005
2Department of Physics and Center for Electro-Optics, University of Nebraska-Lincoln, NE 68588-0111, U. S. A
3State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, Xiamen University, Xiamen 361005
Molecular Dynamics Simulation of MgSiO3 Perovskite
ZHOU Lin-xiang1;J. R. Hardy2;XU Xin3
1Department of Physics, Xiamen University, Xiamen 361005
2Department of Physics and Center for Electro-Optics, University of Nebraska-Lincoln, NE 68588-0111, U. S. A
3State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, Xiamen University, Xiamen 361005
Abstract： Using molecular dynamics to simulate MgSiO3 perovskite is performed to investigate its phase transitions and superionicity. These simulations has used parameter-free Gordon-Kim potentials and a novel technique to monitor the motion of ions which clearly demonstrates the sublattice melting of ions O2- and the rotations of SiO6 octahedra. MgSiO3 has to undergo a few of phase transitions, then enter into the cubic phase. In particular, there is a transitional phase between orthorhombic phase and cubic phase. There are a superionc phase and the cubic phase in magnesium-rich silicate perovskite. This superionic phase occurs after the onset of cubic phase before the melting point. The onset temperature Tc for superionicity is about 200-700K below the melting point Tm, Tc/Tm ~0.92.
1998, Vol. 15 
