Pre melting in iron and iron alloys: ab initio calculations and high P-T experiments on iron, iron alloys and other materials

The questions this proposal seeks to address are these: are the pre-melting effects suggested to occur in iron at the conditions of the Earth's inner core really there, are they seen across PT space in both iron and iron alloys, and are they seen in other materials? If the answer turns out to be "yes", all models for the dynamics and evolution of the Earth's core will have to be re-evaluated.

For over 80 years, the Earth's core has been considered to consist of an iron-nickel alloy, with a few percent of light alloying elements. The pressure range in the core is ~135

1. Who will benefit:
The knowledge arising from this research will lead to a better understanding of the composition, structure and evolution of the Earth's inner core. This fundamental knowledge will primarily interest academics concerned with the evolution of the Earth and other terrestrial planets - geochemists, geophysicists and planetologists. The applied knowledge resulting from this project will benefit metallurgists and material scientists. The general public have an enduring interest in the evolution of the Earth and the planets in our solar system. The media are also keen to report results which have broad public appeal.

2. How will they benefit:
Geochemists, geophysicists and planetologists will gain deeper insight into the physical and chemical properties of planetary cores, which, in turn, may well have implications for our understanding of processes occurring in the mantle. This research will lead to constraints on the material properties of the deep Earth allowing seismologists to better interpret their data. Metallurgists and material scientists will benefit from the new data on pre-melting phenomena and the physical properties of the iron alloys at very high pressures and temperatures. Also, these data are essential in modeling high energy impacts using hydrodynamic codes, where fundamental material properties are used to determine the response of targets to impactors. Even though the end users of this type of knowledge are dominantly academics, the results have great media appeal because of human curiosity concerning the Earth on which we live.

3. What will be done:
Academic beneficiaries: We shall integrate our work into the recently established Paris-UCL Research Exchange programme which aims to foster collaboration between scientists working on the deep Earth at UCL and at the Institut de Physique du Globe de Paris. Broader engagement with material scientists will be made through the UCL Centre for Materials Research, and that with hydrodynamic modellers will be made through the UCL Centre for Planetary Sciences.

Training: One PDRA will be trained in high-pressure/high-temperature experimental techniques, measurement of physical properties and diffraction studies, and will also gain experience working at international large-scale facilities (e.g., APS, ISIS). The other PDRA will gain expertise in simulation methods; this is an area which has been identified as having a national shortfall of trained researchers.

General public: We will set up a Facebook page called "The Earth's Core @UCL" which will give up-to-date background information about the Earth's core together with highlights from our research here at UCL and links, with easy, accessible, explanation, to high quality research elsewhere.

4. Milestones/measures of success
Key outputs will be publications in scientific journals and presentation of the work at international and national conferences. Possible exit-jobs of the PDRAs include work in academia, industrial materials research, computing and mathematical modeling (including the business and financial sectors) as well as scientific administration and journalism.