Elastic Properties of Fe-Ni-Mg at High Pressure from First-Principles Study

Abstract: The purpose of this diploma project has been to investigate the elastic properties of hexagonal close-packed Fe-Ni-Mg alloys at high pressure. Recent research has suggested that iron and magnesium can form an alloy under high pressure because of the great compressibility of the magnesium atoms. This also makes it possible for magnesium alloying with nickel atoms which are very similar to iron so that we get Fe-Ni-Mg alloys. Learning more about the elastic properties of iron alloys at high pressure will give us a better understanding of the inner core of our planet, which is believed to be composed primarily of iron. The calculations are based on a ab-inito method supported on the Density Functional Theory. The calculations were performed with a simulation package based on the Exact Muffin-Tin Orbitals theory, in conjuction with the Coherent Potential Approximation. The effects that small impurities can have on iron are remarkable.