Pure Iron Compressed and Heated to Extreme Conditions

ORAL

Abstract

The results of a first-principles study supported by the temperature-quenched laser-heated diamond anvil-cell experiments on the high-pressure high-temperature structural behavior of pure iron are reported. We show that in contrast to the widely accepted picture, the face-centered cubic (fcc) phase becomes as stable as the hexagonal-close-packed (hcp) phase at pressures around 300–360 GPa and temperatures around 5000–6000 K. Our temperature-quenched experiments indicate that the fcc phase of iron can exist in the pressure-temperature region above 160 GPa and 3700 K, respectively. This, in particular, means that the actual structure of the Earth's core may be a complex phase with a large number of stacking faults.

*Acknowledgement to the ESF program ``Mineralogy and Chemistry of Earth's core (MCEC)", Swedish Research Council (VR), Swedish Foundation for Strategic Research (SSF), Swedish National Infrastructure for Computing (SNIC), Deutsche Forschungsgemeinschaf

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Authors

  • Arkady Mikhaylushkin

    • Theory and Modeling Division, Department of Physics, Chemistry and Biology (IFM), Link\"oping University, S-581 83, Link\"oping, Sweden
    • Department of Physics, Chemistry and Biology, Linkoping University, Sweden

  • Sergei Simak

    • Department of Physics, Chemistry and Biology, Linkoping University, Sweden
    • Theory and Modeling Division, Department of Physics, Chemistry and Biology (IFM), Link\"oping University, S-581 83, Link\"oping, Sweden

  • Leonid Dubrovinsky

    • Bayerisches Geoinstitut, Universitat Bayreuth, D-95440 Bayreuth, Germany

  • Natalia Dubrovinskaia

    • Mineralphysik und Strukturforschung, Mineralogisches Institut, Universit\"at Heidelberg, 69120 Heidelberg, Germany

  • Borje Johansson

    • Applied Materials Physics, Department of Materials and Engineering, Royal Institute of Technology (KTH), SE-10044 Stockholm, Sweden

  • Igor Abrikosov

    • Theory and Modeling Division, Department of Physics, Chemistry and Biology (IFM), Link\"oping University, S-581 83, Link\'oping, Sweden