First-Principles Study of Elastic Properties of Fe-Mg alloy at Earth’s core pressure
Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
The purpose of this thesis has been to investigate the elastic properties of an fcc FeMg alloy with 10 at.% magnesium under high pressure. Recent research has shown that magnesium can be a possible candidate for light element impurities in the Earth’s inner core, something that was previously not considered possible because of the low miscibility of magnesium in iron at ambient pressure. Gaining knowledge about the composition of the Earth’s core can help us better understand such phenomena as seismic activity and the fluctuations of the Earth’s magnetic field.
The elastic constants of the FeMg alloy was calculated using ab-initio methods based on Density Functional Theory. The Exact Muffin-Tin Orbitals method was used in conjunction with the Coherent Potential Approximation.
The FeMg alloy was found to be overall considerably softer than pure iron, and the softening effect on the elastic constants was also found to increase with pressure. The results also showed that 10% Mg alloying increased the anisotropy with about 40% compared to pure iron.
Place, publisher, year, edition, pages
2008. , 32 p.
Density Functional Theory, EMTO, Earth’s core, High-Pressure Alloying, Fe-Mg alloy, Elastic Constants
IdentifiersURN: urn:nbn:se:liu:diva-15742ISRN: LiTH-IFM-G-EX-08/2011-SEOAI: oai:DiVA.org:liu-15742DiVA: diva2:127211
2008-10-16, Mott, Fysikhuset, Linköpings Universitet, Linköping, 11:00 (English)
Abrikosov, Igor, ProfessorAsker, Christian, Doktorand
Abrikosov, Igor, Professor