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Title: High-Pressure Geophysical Properties of Fcc Phase FeHX

Journal Article · · Geochemistry, Geophysics, Geosystems
DOI:https://doi.org/10.1002/2017GC007168· OSTI ID:1459894
ORCiD logo [1]; ORCiD logo [1];  [2]; ORCiD logo [3]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [5]; ORCiD logo [5];  [1]
  1. Univ. of Chicago, IL (United States). Dept. of the Geophysical Sciences
  2. Univ. of Illinois, Urbana, IL (United States). Dept. of Geology; Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
  3. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
  4. Univ. of Hawaii Manoa, Honolulu, HI (United States). Hawaii Inst. of Geophysics & Planetology
  5. Univ. of Chicago, IL (United States). Center for Advanced Radiation Sources (CARS)
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Abstract Face centered cubic ( fcc ) FeH X was synthesized at pressures of 18–68 GPa and temperatures exceeding 1,500 K. Thermally quenched samples were evaluated using synchrotron X‐ray diffraction (XRD) and nuclear resonant inelastic X‐ray scattering (NRIXS) to determine sample composition and sound velocities to 82 GPa. To aid in the interpretation of nonideal (X ≠ 1) stoichiometries, two equations of state for fcc FeH X were developed, combining an empirical equation of state for iron with two distinct synthetic compression curves for interstitial hydrogen. Matching the density deficit of the Earth's core using these equations of state requires 0.8–1.1 wt % hydrogen at the core‐mantle boundary and 0.2–0.3 wt % hydrogen at the interface of the inner and outer cores. Furthermore, a comparison of Preliminary Reference Earth Model (PREM) to a Birch's law extrapolation of our experimental results suggests that an iron alloy containing ∼0.8–1.3 wt % hydrogen could reproduce both the density and compressional velocity ( V P ) of the Earth's outer core.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
National Science Foundation (NSF); National Science Foundation (NSF) - Directorate for Geosciences Division of Earth Sciences (GEO/EAR); USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-06CH11357; DE‐FG02‐94ER14466
OSTI ID:
1459894
Alternate ID(s):
OSTI ID: 1418420
Journal Information:
Geochemistry, Geophysics, Geosystems, Vol. 19, Issue 1; ISSN 1525-2027
Publisher:
American Geophysical UnionCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 31 works
Citation information provided by
Web of Science

References (45)

Iron hydride formed by the reaction of iron, silicate, and water: Implications for the light element of the Earth's core journal July 1995
Synthesis of quenchable amorphous diamond journal August 2017
X-ray diffraction and Mössbauer spectroscopy study of fcc iron hydride FeH at high pressures and implications for the composition of the Earth's core journal July 2011
Elasticity and constitution of the Earth's interior journal June 1952
Calculated melting curves for phases of iron journal February 2000
Light elements in the Earth's outer core: A critical review journal September 1994
High-Pressure Chemistry of Hydrogen in Metals: In Situ Study of Iron Hydride journal July 1991
Iron-water reaction at high pressure and temperature, and hydrogen transport into the core journal March 2005
Sound velocity of hexagonal close‐packed iron up to core pressures journal October 2013
High pressure metal–silicate partitioning of Ni, Co, V, Cr, Si, and O journal October 2015
Pressure effect on the electronic structure of iron in (Mg,Fe)(Si,Al)O3 perovskite: a combined synchrotron Mössbauer and X-ray emission spectroscopy study up to 100 GPa journal September 2006
Melting phase relation of FeHx up to 20GPa: Implication for the temperature of the Earth's core journal May 2009
Hydrogen in the earth's core. Experimental approach. journal January 1983
Phonon Density of States of Iron up to 153 Gigapascals journal May 2001
Measurement of temperature distributions across laser heated samples by multispectral imaging radiometry journal January 2008
Diamond anvil Raman gauge in multimegabar pressure range journal December 2007
Compression of iron hydride to 80 GPa and hydrogen in the Earth's inner core: COMPRESSION OF IRON HYDRIDE TO 80 GPA journal March 2004
Sound velocity of hcp-Fe at high pressure: experimental constraints, extrapolations and comparison with seismic models journal March 2015
Another look at the core density deficit of Earth’s outer core journal June 2002
DIOPTAS : a program for reduction of two-dimensional X-ray diffraction data and data exploration journal May 2015
Finite strain isotherm and velocities for single-crystal and polycrystalline NaCl at high pressures and 300°K journal January 1978
First-Principles Study on the Structural and Magnetic Properties of Iron Hydride journal June 2012
Simultaneous sound velocity and density measurements of hcp iron up to 93GPa and 1100K: An experimental test of the Birch's law at high temperature journal May 2012
The influence of hydrogen on the seismic properties of solid iron journal May 2015
Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions journal January 1986
Hydrogen in the Earth's core journal July 1977
Effects of the Fe3+ spin transition on the properties of aluminous perovskite—New insights for lower-mantle seismic heterogeneities journal October 2011
Effect of light elements on the sound velocities in solid iron: Implications for the composition of Earth's core journal February 2007
Magma redox and structural controls on iron isotope variations in Earth's mantle and crust journal July 2014
New Iron Hydrides under High Pressure journal December 2014
Elasticity and rheology of iron above 220 GPa and the nature of the Earth's inner core journal December 1998
Nuclear resonant x-ray scattering of iron hydride at high pressure journal January 2004
Advanced flat top laser heating system for high pressure research at GSECARS: application to the melting behavior of germanium journal September 2008
Equation of state of γ-Fe: Reference density for planetary cores journal August 2013
Models of the Earth's Core journal November 1981
Quasihydrostatic Equation of State of Iron above 2 Mbar journal November 2006
Sound Velocities of Hot Dense Iron: Birch's Law Revisited journal June 2005
The MD simulation of the equation of state of MgO: Application as a pressure calibration standard at high temperature and high pressure journal February 2000
The phase diagram and superabundant vacancy formation in Fe–H alloys under high hydrogen pressures journal January 2003
Neutron diffraction investigation of the dhcp and hcp iron hydrides and deuterides journal January 1998
Hydrogen in the Deep Earth journal May 2001
Preliminary reference Earth model journal June 1981
Composition and temperature of Earth's inner core journal November 1997
Is the inner core of the Earth pure iron? journal January 1987
Sound velocity measurements in dhcp-FeH up to 70GPa with inelastic X-ray scattering: Implications for the composition of the Earth's core journal January 2012

Cited By (2)

Interstitial hydrogen atoms in face-centered cubic iron in the Earth’s core journal May 2019
Hydrogen Limits Carbon in Liquid Iron journal May 2019

Figures / Tables (7)

Figure 1(p. 15)figure Figure 1
Figure 2(p. 16)figure Figure 2
Figure 3(p. 17)figure Figure 3
Figure 4(p. 18)figure Figure 4
Table 1(p. 19)table Table 1
Table 2(p. 20)table Table 2
Table 3(p. 21)table Table 3

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Related Subjects

58 GEOSCIENCES
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
core
hydrogen
equation of state
X-ray diffraction
nuclear resonant inelastic X-ray scattering
synchrotron Mössbauer spectroscopy