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 Article · Fri Oct 28 04:00:00 EDT 2011 · Earth Planet. Sci. Lett.

DOI:https://doi.org/10.1016/j.epsl.2011.05.015· OSTI ID:1024506

Narygina, Olga; Dubrovinsky, Leonid S; McCammon, Catherine A; Kurnosov, Alexander; Kantor, Innokenty Yu; Prakapenka, Vitali B; Dubrovinskaia, Natalia A ^[1]

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1. Bayreuth

The phase fcc FeH{sub x} (x {approx} 1) was synthesized at pressures over 30 GPa and temperatures over 1600(50) K. At room temperature this iron hydride is stable at pressures from 19(1) GPa up to at least 68(2) GPa (the highest pressure achieved in this study). A fit of the PV data collected for fcc FeH{sub x} at room temperature gives the following parameters for the equation of state: V{sub 0} = 53.8(3) {angstrom}{sup 3}, K{sub 0} = 99(5) GPa, K' = 11.7(5). Using this data the amount of H required to match the density of the Earth's core was estimated to be 0.5-1 wt.% hydrogen in the outer core and 0.08-0.16 wt.% hydrogen in the inner core. Our results also suggest that hydrogen and carbon do not occur together in the Earth's core.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: FOREIGN
• OSTI ID: 1024506
• Journal Information: Earth Planet. Sci. Lett., Journal Name: Earth Planet. Sci. Lett. Journal Issue: (3-4) ; 07, 2011 Vol. 307; ISSN 0012-821X; ISSN EPSLA2
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

58 GEOSCIENCES
AMBIENT TEMPERATURE
CARBON
EARTH CORE
EQUATIONS OF STATE
HYDROGEN
IRON HYDRIDES
MOESSBAUER EFFECT
PRESSURE RANGE GIGA PA
TEMPERATURE RANGE 1000-4000 K
X-RAY DIFFRACTION