Synthesis and Equation of State of (Mg,Fe) SiO 3 Perovskite to Over 100 Gigapascals
- 6 February 1987
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 235 (4789) , 668-670
- https://doi.org/10.1126/science.235.4789.668
Abstract
Silicate perovskite of composition (Mg0.88Fe0.12) SiO3 has been synthesized in a laser-heated diamond-anvil cell to a pressure of 127 gigapascals at temperatures exceeding 2000 K. The perovskite phase was identified and its unit-cell dimensions measured by in situ x-ray diffraction at elevated pressure and room temperature. An analysis of these data yields the first high-precision equation of state for this mineral, with values of the zero-pressure isothermal bulk modulus and its pressure derivative being K0T = 266 ± 6 gigapascals and K'0T = 3.9 ± 0.4. In addition, the orthorhombic distortion of the silicate-perovskite structure away from ideal cubic symmetry remains constant with pressure: the lattice parameter ratios are b/a = 1.032 ± 0.002 and c/a = 1.444 ± 0.006. These results, which prove that silicate perovskite is stable to ultrahigh pressures, demonstrate that perovskite can exist throughout the pressure range of the lower mantle and that it is therefore likely to be the most abundant mineral in Earth.Keywords
This publication has 20 references indexed in Scilit:
- Synthesis and crystal-chemical characterization of MgSiO3 perovskitePublished by Elsevier ,2002
- Garnet phase of MgSiO3 filling the pyroxene–ilmenite gap at very high temperatureNature, 1985
- Lattice dynamics and structural distortions of CaSiO3 and MgSiO3 perovskitesGeophysical Research Letters, 1985
- Phase transitions and mantle discontinuitiesReviews of Geophysics, 1983
- Preliminary reference Earth modelPhysics of the Earth and Planetary Interiors, 1981
- Transmission electron diffraction and microscopy of synthetic high pressure MgSiO3 phase with perovskite structureGeophysical Research Letters, 1980
- High-pressure phase equilibria in a garnet lherzolite, with special reference to Mg2+Fe2+ partitioning among constituent mineralsPhysics of the Earth and Planetary Interiors, 1979
- Composition of the Mantle and CoreAnnual Review of Earth and Planetary Sciences, 1977
- Orthorhombic perovskite phases observed in olivine, pyroxene and garnet at high pressures and temperaturesPhysics of the Earth and Planetary Interiors, 1976
- Equations of state and crystal structures of high‐pressure phases of shocked silicates and oxidesReviews of Geophysics, 1969