TY - JOUR
T1 - Melting of iron-silicon alloy up to the core-mantle boundary pressure
T2 - Implications to the thermal structure of the Earth's core
AU - Asanuma, Hidetoshi
AU - Ohtani, Eiji
AU - Sakai, Takeshi
AU - Terasaki, Hidenori
AU - Kamada, Seiji
AU - Kondo, Tadashi
AU - Kikegawa, Takumi
N1 - Funding Information:
The authors thank Akio Suzuki for his valuable discussion, and Masaaki Miyahara and Yoshinori Ito for their help for sample preparation and scanning electron microscopy. The authors also appreciate Nobumasa Funamori and an anonymous reviewer for their constructive reviews. This study was conducted at the beamline BL13A of Photon Factory, KEK (proposal no. 2005G151 and no. 2006G270). This work was partially supported by the Grant-in-Aid for Scientific Research to E. O. (no. 16075202 and no. 18104009) and T. K. (no. 16340164) from Ministry of Education, Culture, Sports, Science, and Technology of the Japanese Government and conducted as a part of the Global Center-of-Excellence program “Global Research and Education Center for the Dynamics of the Earth and Planets”.
PY - 2010/6
Y1 - 2010/6
N2 - The melting temperature of Fe-18 wt% Si alloy was determined up to 119 GPa based on a change of laser heating efficiency and the texture of the recovered samples in the laser-heated diamond anvil cell experiments. We have also investigated the subsolidus phase relations of Fe-18 wt% Si alloy by the in-situ X-ray diffraction method and confirmed that the bcc phase is stable at least up to 57 GPa and high temperature. The melting curve of the alloy was fitted by the Simon's equation, P(GPa)/a = (Tm(K)/T0)c, with parameters, T0 = 1,473 K, a = 3.5 ± 1.1 GPa, and c = 4.5 ± 0.4. The melting temperature of bcc Fe-18 wt% Si alloy is comparable with that of pure iron in the pressure range of this work. The melting temperature of Fe-18 wt% Si alloy is estimated to be 3,300-3,500 K at 135 GPa, and 4,000-4,200 K at around 330 GPa, which may provide the lower bound of the temperatures at the core-mantle boundary and the inner core-outer core boundary if the light element in the core is silicon.
AB - The melting temperature of Fe-18 wt% Si alloy was determined up to 119 GPa based on a change of laser heating efficiency and the texture of the recovered samples in the laser-heated diamond anvil cell experiments. We have also investigated the subsolidus phase relations of Fe-18 wt% Si alloy by the in-situ X-ray diffraction method and confirmed that the bcc phase is stable at least up to 57 GPa and high temperature. The melting curve of the alloy was fitted by the Simon's equation, P(GPa)/a = (Tm(K)/T0)c, with parameters, T0 = 1,473 K, a = 3.5 ± 1.1 GPa, and c = 4.5 ± 0.4. The melting temperature of bcc Fe-18 wt% Si alloy is comparable with that of pure iron in the pressure range of this work. The melting temperature of Fe-18 wt% Si alloy is estimated to be 3,300-3,500 K at 135 GPa, and 4,000-4,200 K at around 330 GPa, which may provide the lower bound of the temperatures at the core-mantle boundary and the inner core-outer core boundary if the light element in the core is silicon.
KW - Core
KW - FeSi alloy
KW - High pressure
KW - Melting
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U2 - 10.1007/s00269-009-0338-7
DO - 10.1007/s00269-009-0338-7
M3 - Article
AN - SCOPUS:77953028580
VL - 37
SP - 353
EP - 359
JO - Physics and Chemistry of Minerals
JF - Physics and Chemistry of Minerals
SN - 0342-1791
IS - 6
ER -