title: Iron-silicon alloy in Earth's core?
abstract: We have investigated the phase relations in the iron-rich portion of the iron-silicon (Fe-Si) alloys at high pressures and temperatures. Our study indicates that Si alloyed with Fe can stabilize the body-centered cubic (bcc) phase up to at least 84 gigapascals (compared to approximately 10 gigapascals for pure Fe) and 2400 kelvin. Earth's inner core may be composed of hexagonal close-packed (hcp) Fe with up to 4 weight percent Si, but it is also conceivable that the inner core could be a mixture of a Si-rich bcc phase and a Si-poor hcp phase.
authors.affiliation: Department of the Geophysical Sciences, James Franck Institute, Consortium for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637, USA. afu@geosci.uchicago.edu
authors.forename: Jung-Fu
authors.initials: JF
authors.lastname: Lin
authors.forename: Dion L
authors.initials: DL
authors.lastname: Heinz
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Campbell
authors.forename: James M
authors.initials: JM
authors.lastname: Devine
authors.forename: Guoyin
authors.initials: G
authors.lastname: Shen