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

Title data

Narygina, Olga ; Dubrovinsky, Leonid ; McCammon, Catherine ; Kurnosov, Alexander ; Kantor, Innokenty ; Prakapenka, Vitali B. ; Dubrovinskaia, Natalia:
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.
In: Earth and Planetary Science Letters. Vol. 307 (2011) Issue 3–4 . - pp. 409-414.
ISSN 0012-821X
DOI: https://doi.org/10.1016/j.epsl.2011.05.015

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Abstract in another language

The phase fcc FeHx (x ~ 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 FeHx at room temperature gives the following parameters for the equation of state: {V0} = 53.8(3) Å3, {K0} = 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.