Effect of pressure on the crystal structure of perovskite-type MgSiO3

The crystal structure of perovskite-type MgSiO3 has been studied up to 96 kbar, using a miniature diamondanvil pressure cell and by means of single-crystal four-circle diffractometry. The observed unit cell compression gives a bulk modulus of Ko=2.47 Mbar, assuming K′o=4. The unit cell compression is controlled mainly by the tilting of SiO6 octahedra. The effect of pressure is to change Mg polyhedron towards 8-fold coordination rather than 12-fold coordination. The polyhedral bulk moduli of SiO6 and MgO8 are 3.8 Mbar and 1.9 Mbar, respectively.

[1]  Lin-Gun Liu,et al.  Calculations of high-pressure phase transitions in the system MgOSiO2 and implications for mantle discontinuities , 1979 .

[2]  R. Hazen.  Comparative crystal chemistry , 1982 .

[3]  D. Weidner,et al.  Crystal growth of MgSiO3 perovskite , 1986 .

[4]  E. Ito,et al.  Synthesis and crystal-chemical characterization of MgSiO3 perovskite , 1978 .

[5]  A. E. Ringwood,et al.  Elasticity of aluminate, titanate, stannate and germanate compounds with the perovskite structure , 1977 .

[6]  W. C. Hamilton,et al.  Anisotropic extinction corrections in the Zachariasen approximation , 1970 .

[7]  James A. Ibers,et al.  International tables for X-ray crystallography , 1962 .

[8]  Takeo Matsumoto,et al.  Computational model of the structural and elastic properties of the ilmenite and perovskite phases of MgSiO3 , 1987 .

[9]  A. E. Ringwood,et al.  Mineralogical constitution of the deep mantle , 1962 .

[10]  Larry W. Finger,et al.  A revised method of operation of the single-crystal diamond cell and refinement of the structure of NaCl at 32 kbar , 1978 .

[11]  H. Schulz,et al.  A new measuring procedure for data collection with a high-pressure cell on an X-ray four-circle diffractometer , 1978 .

[12]  A. E. Ringwood,et al.  High-pressure modification of ScAlO3 and some geophysical implications , 1975 .

[13]  H. Takeda,et al.  An attempt to simulate high pressure structures of Mg-silicates by an energy minimization method , 1984 .

[14]  Lin‐gun Liu.  Post-oxide phases of forsterite and enstatite , 1975 .

[15]  M. O'keeffe,et al.  Contribution to the crystal chemistry of orthorhombic perovskites: MgSiO3 and NaMgF3 , 1979 .

[16]  Stanley Block,et al.  An Optical Fluorescence System for Quantitative Pressure Measurement in the Diamond‐Anvil Cell , 1973 .

[17]  Stanley Block,et al.  Hydrostatic limits in liquids and solids to 100 kbar , 1973 .

[18]  Ho-kwang Mao,et al.  Structure and crystal chemistry of perovskite-type MgSiO3 , 1978 .

[19]  H. Mao,et al.  Hydrostatic Compression of Perovskite-Type MgSiO3 , 1982 .

[20]  Yasuhiro Kudoh,et al.  The crystal structure of forsterite Mg2SiO4 under high pressure up to 149 kb , 1985 .

[21]  Robert M. Hazen,et al.  Crystal structures and compressibilities of pyrope and grossular to 60 kbar , 1978 .

[22]  L. Finger,et al.  Diffracted beam crystal centering and its application to high‐pressure crystallography , 1979 .

[23]  Lin-gun Liu,et al.  Silicate perovskite from phase transformations of pyrope‐garnet at high pressure and temperature , 1974 .