Iron-silicon Alloy in Earth's Core?
Affiliations
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.
High Pressure Melting Curve of Fe-Si: Implication for the Thermal Properties in Mercury's Core.
Ezenwa I, Fei Y, Hrubiak R, Kenney-Benson C J Geophys Res Planets. 2024; 129(12):e2024JE008353.
PMID: 39619888 PMC: 11605165. DOI: 10.1029/2024JE008353.
Iron alloys of volatile elements in the deep Earth's interior.
Tian Y, Zhang P, Zhang W, Feng X, Redfern S, Liu H Nat Commun. 2024; 15(1):3320.
PMID: 38637525 PMC: 11026407. DOI: 10.1038/s41467-024-47663-0.
Iron-rich Fe-O compounds at Earth's core pressures.
Liu J, Sun Y, Lv C, Zhang F, Fu S, Prakapenka V Innovation (Camb). 2022; 4(1):100354.
PMID: 36457892 PMC: 9707061. DOI: 10.1016/j.xinn.2022.100354.
Superionic iron alloys and their seismic velocities in Earth's inner core.
He Y, Sun S, Kim D, Jang B, Li H, Mao H Nature. 2022; 602(7896):258-262.
PMID: 35140389 DOI: 10.1038/s41586-021-04361-x.
The Fe-FeSi phase diagram at Mercury's core conditions.
Edmund E, Morard G, Baron M, Rivoldini A, Yokoo S, Boccato S Nat Commun. 2022; 13(1):387.
PMID: 35046422 PMC: 8770642. DOI: 10.1038/s41467-022-27991-9.