Melting properties of iron alloys under Earth's core conditions

摘要: The liquid core of the Earth extends between 2900 km and 5150 km depth accounting for 18% of the total planetary volume. Although mostly composed of iron, it contains impurities that lower its density and melting point with respect to pure Fe. Knowledge of the nature and content in light elements (O, S, Si, C) in the core has major implications for establishing the bulk composition of the Earth and for building models of Earth's differentiation. Angle dispersive X-ray diffraction experiments in double-sided laser heated diamond anvil cell (LH-DAC) were performed at ID27 beamline at the European Synchrotron Radiation Facility (ESRF) in Grenoble. In situ investigations enable determination of melting temperature and structural and density properties of the liquid alloys. Experiments were performed on the Fe-Ni-S alloy up to 160 GPa and 4000 K, on the Fe-Ni-Si alloy up to 91 GPa and 3200 K, on the Fe-FeO system …