Dynamical stability of Fe-H in the Earth's mantle and core regions
2007 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 104, no 22, 9168-9171 p.Article in journal (Refereed) Published
The core extends from the depth of 2,900 km to the center of the Earth and is composed mainly of an iron-rich alloy with nickel, with 10% of the mass comprised of lighter elements like hydrogen, but the exact composition is uncertain. We present a quantum mechanical first-principles study of the dynamical stability of FeH phases and their phonon densities of states at high pressure. Our free-energy calculations reveal a phonon-driven stabilization of dhcp FeH at low pressures, thus resolving the present contradiction between experimental observations and theoretical predictions. Calculations reveal a complex phase diagram for FeH under pressure with a dhcp -> hcp -> fcc sequence of structural transitions.
Place, publisher, year, edition, pages
2007. Vol. 104, no 22, 9168-9171 p.
high pressure, iron hydride, phonons and phase transition, solid Earth, sound velocity
IdentifiersURN: urn:nbn:se:uu:diva-145288DOI: 10.1073/pnas.0609701104ISI: 000246935700016OAI: oai:DiVA.org:uu-145288DiVA: diva2:396121