Iron silicides at pressures of the Earth's inner core
MetadataShow full item record
The Earth's core is expected to contain around 10 wt % light elements (S, Si, O, possibly C, H, etc.) alloyed with Fe and Ni. Very little is known about these alloys at pressures and temperatures of the core. Here, using the evolutionary crystal structure prediction methodology, we investigate Fe-Si compounds at pressures of up to 400 GPa, i.e. covering the pressure range of the Earth's core. Evolutionary simulations correctly find that at atmospheric pressure the known non-trivial structure with P213 symmetry is stable,while at pressures above 20 GPa the CsCl-type structure is stable. We show that among the possible Fe silicides (Fe3Si,Fe2Si, Fe5Si3, FeSi, FeSi2 and FeSi3) only FeSi with CsCl type structure is thermodynamically stable at core pressures, while the other silicides are unstable to decomposition into Fe + FeSi or FeSi + Si. This is consistent with previous works and suggests that Si impurities contribute to stabilization of the body-centered cubic phase of Fe in the inner core.
©2010. American Geophysical Union
Showing items related by title, author, creator and subject.
Investigation of pressure and saturation effects on elastic parameters: an integrated approach to improve time-lapse interpretationGrochau, Marcos Hexsel (2009)Time-lapse seismic is a modern technology for monitoring production-induced changes in and around a hydrocarbon reservoir. Time-lapse (4D) seismic may help locate undrained areas, monitor pore fluid changes and identify ...
Bryant, Alan R. (2001)Hallux valgus and hallux limitus are two common foot pathologies that may require surgical intervention. While the modified Austin bunionectomy and the Youngswick osteotomy/cheilectomy respectively, are often used to ...
Johnson, Sarah E. (2010)Parental time pressure, in terms of actual workload and subjective reports, is high and likely to increase in the future, with ongoing implications for personal wellbeing. The combination of parenting young children and ...