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Unit cell determination of coexisting post-perovskite and H-phase in (Mg,Fe)SiO3 using multigrain XRD: compositional variation across a laser heating spot at 119 GPa

Journal Article · · Progress in Earth and Planetary Science
 [1];  [2];  [3]
  1. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China); Center for High Pressure Science and Technology Advanced Research (HPSTAR)Shanghai, China
  2. Carnegie Inst. of Washington, Argonne, IL (United States). Geophysical Lab., High Pressure Collaborative Access Team (HPCAT)
  3. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China); Carnegie Inst. of Washington, Washington, DC (United States). Geophysical Lab.
+ Show Author Affiliations
Multigrain X-ray diffraction (XRD) can be used to accurately calculate the unit cell parameters of individual mineral phases in a mineral assemblage contained in a diamond anvil cell (DAC). Coexisting post-perovskite (ppv) and H-phase were synthesized at 119 GPa and 2500 K from (Mg0.85Fe0.15)SiO3 in a laser-heated DAC. The unit cell parameters of the ppv and coexisting H-phase were determined using multigrain XRD with a 5 μm spatial resolution, close to the size of the X-ray beam, to understand compositional variations across the center area (20–30 μm) in a laser-heated sample. The ppv phase was Fe-depleted and the unit cell volume of ppv decreased by only 0.16 % (corresponding to ~3 % variation of FeSiO3) from the heating center to 10 μm off the center, while the sample pressure remained at 119 GPa in a Ne quasi-hydrostatic environment. The unit cell volume of the H-phase decreased by 0.54 % (~10 % variation of FeSiO3 content) over the same 10 μm distance. Both phases were more Fe-enriched in the slightly hotter center. This observation suggests that thermal diffusion may not be the major driver for the compositional variations of ppv and H-phase in the center portion of a laser-heated sample. Instead, these variations could be caused by a temperature effect on the partitioning between the ppv and H-phase over the small gradient.
Research Organization:
Carnegie Inst. of Washington, Washington, DC (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
AC02-06CH11357; FG02-94ER14466; FG02-99ER45775; NA0001974
OSTI ID:
1466599
Alternate ID(s):
OSTI ID: 1262435
Journal Information:
Progress in Earth and Planetary Science, Journal Name: Progress in Earth and Planetary Science Journal Issue: 1 Vol. 3; ISSN 2197-4284
Publisher:
Springer OpenCopyright Statement
Country of Publication:
United States
Language:
English

References (19)

Partitioning of iron between perovskite/postperovskite and ferropericlase in the lower mantle journal January 2008
Equations of state of six metals above 94 GPa journal September 2004
Phase transition in MgSiO3 perovskite in the earth's lower mantle journal August 2004
Effect of pressure and composition on lattice parameters and unit-cell volume of (Fe,Mg)SiO3 post-perovskite journal February 2012
Effects of Fe-enrichment on the equation of state and stability of (Mg,Fe)SiO3 perovskite journal January 2013
Effect of Fe on the equation of state of mantle silicate perovskite over 1Mbar journal May 2008
First-principles prediction of the P - V - T equation of state of gold and the 660-km discontinuity in Earth's mantle : FIRST-PRINCIPLES PREDICTION OF EQUATION OF STATE OF GOLD journal October 2003
High resolution three-dimensional X-ray diffraction study of dislocations in grains of MgGeO 3 post-perovskite at 90 GPa : DISLOCATIONS IN GRAINS OF MgGeO journal March 2012
Synchrotron radiation and laser heating in a diamond anvil cell journal January 2001
New developments in laser-heated diamond anvil cell with in situ synchrotron x-ray diffraction at High Pressure Collaborative Access Team journal July 2015
Toward an internally consistent pressure scale journal May 2007
Single-crystal structure determination of (Mg,Fe)SiO3 postperovskite journal April 2013
Equations of state of six metals above 94 GPa journal September 2004
GrainSpotter : a fast and robust polycrystalline indexing algorithm journal January 2014
In situ monitoring of phase transformation microstructures at Earth's mantle pressure and temperature using multi-grain XRD journal August 2015
Disproportionation of (Mg,Fe)SiO3 perovskite in Earth's deep lower mantle journal May 2014
Unit cell refinement from powder diffraction data: the use of regression diagnostics journal February 1997
Multigrain crystallography journal January 2012
Application of FIB system to ultra-high-pressure Earth science journal January 2008

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Related Subjects

58 GEOSCIENCES
Diamond anvil cell
H-phase
Lower mantle
Multigrain XRD
Post-perovskite
Synchrotron X-ray
Unit cell