高温高圧下におけるFe-S-Siの化学的及び物理的性質：惑星核への応用

Tohoku University鈴木昭夫課

Melting relations in the Fe–S–Si system at high pressure and temperature: implications for the planetary core

Abstract The phase and melting relations in the Fe–S–Si system were determined up to 60 GPa by using a double-sided laser-heated diamond anvil cell combined with X-ray diffraction. On the basis of the X-ray diffraction patterns, we confirmed that hcp/fcc Fe–Si alloys and Fe3S are stable phases under subsolidus conditions in the Fe–S–Si system. Both solidus and liquidus temperatures are significantly lower than the melting temperature of pure Fe and both increase with pressure. The slopes of the Fe–S–Si liquidus and solidus curves determined here are smaller than the adiabatic temperature gradients of the liquid cores of Mercury and Mars. Thus, crystallization of their cores started at the core–mantle boundary region

Additional file 1: of Melting relations in the Fe–S–Si system at high pressure and temperature: implications for the planetary core

a 2D images of diffraction patterns of the Fe–S–Si system at 42.3–44.1 GPa (Run FESSI20) corresponding to the X-ray profile given in Figure 1(a). A at 44(1) GPa and 1450(50) K, B at 44(4) GPa and 1650(50) K, C at 44(4) GPa and 1730(50) K, and D at 42.2(0.3) GPa and 300 K after quenching from 1730 K. NaCl was used as the pressure medium and thermal insulator. b 2D images of diffraction patterns of the Fe−S−Si system at 49.2-58.2 GPa (Run FESSI10) corresponding to the X-ray profile given in Figure 1(b). A at 58(5) GPa and 1650(50) K, B at 54(4) GPa and 1810(50) K, C at 54(4) GPa and 1840(50) K, and D at 49.2(0.6) GPa and 300 K after quenching from 1840 K. (DOCX 1725 kb