研究进展

朱峰等,JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2021

发表时间:2021-11-26来源:ok138太阳集团中国官方网站点击:

Density of Fe-Ni-C Liquids at High Pressures and Implications for Liquid Cores of Earth and the Moon

作者

Zhu, F (Zhu, Feng) Lai, XJ (Lai, Xiaojing) Wang, JW (Wang, Jianwei) Amulele, G (Amulele, George) Kono, Y (Kono, Yoshio) Shen, GY (Shen, Guoyin) Jing, ZC (Jing, Zhicheng) Manghnani, MH (Manghnani, Murli H.) Williams, Q (Williams, Quentin) Chen, B (Chen, Bin)

(由 Clarivate 提供)

126

3

文献号

e2020JB021089

DOI

10.1029/2020JB021089

出版时间

MAR 2021

文献类型

Article

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摘要

The presence of light elements in the metallic cores of the Earth, the Moon, and other rocky planetary bodies has been widely proposed. Carbon is among the top candidates in light of its high cosmic abundance, siderophile nature, and ubiquity in iron meteorites. It is, however, still controversial whether carbon-rich core compositional models can account for the seismic velocity observations within the Earth and lunar cores. Here, we report the density and elasticity of Fe90Ni10-3 wt.% C and Fe90Ni10-5 wt.% C liquid alloys using synchrotron-based X-ray absorption experiments and first-principles molecular dynamics simulations. Our results show that alloying of 3 wt.% and 5 wt.% C lowers the density of Fe90Ni10 liquid by similar to 2.9-3.1% at 2 GPa, and similar to 3.4-3.6% at 9 GPa. More intriguingly, our experiments and simulations both demonstrate that the bulk moduli of the Fe-Ni-C liquids are similar to or slightly higher than those of Fe-Ni liquids. Thus, the calculated compressional velocities (v(p)) of Fe-Ni-C liquids are higher than that of pure Fe-Ni alloy, promoting carbon as a possible candidate to explain the elevated v(p) in the Earth's outer core. However, the values and slopes of both density and v(p) of the studied two Fe-Ni-C liquids do not match the outer core seismic models, suggesting that carbon may not be the sole principal light element in Earth's outer core. The high v(p) of Fe-Ni-C liquids does not match the presumptive v(p) of the lunar outer core well, indicating that carbon is less likely to be its dominant light element.

关键词

作者信息

通讯作者地址

Chen, Bin

(通讯作者)

Univ Hawaii Manoa, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA

所属机构

University of Hawaii System
University of Hawaii Manoa

通讯作者地址

Wang, Jianwei

(通讯作者)

Louisiana State Univ, Ctr Computat & Technol, Dept Geol & Geophys, Baton Rouge, LA 70803 USA

电子邮件地址

binchen@hawaii.edu jianwei@lsu.edu

类别/分类

研究方向

Geochemistry & Geophysics

基金资助