极端条件下液态铁的状态方程

Equation of State of Liquid Iron under Extreme Conditions.

作者信息

Kuwayama Yasuhiro, Morard Guillaume, Nakajima Yoichi, Hirose Kei, Baron Alfred Q R, Kawaguchi Saori I, Tsuchiya Taku, Ishikawa Daisuke, Hirao Naohisa, Ohishi Yasuo

机构信息

Department of Earth and Planetary Science, The University of Tokyo, 113-0033 Tokyo, Japan.

Geodynamics Research Center, Ehime University, 790-8577 Ehime, Japan.

出版信息

Phys Rev Lett. 2020 Apr 24;124(16):165701. doi: 10.1103/PhysRevLett.124.165701.

DOI:10.1103/PhysRevLett.124.165701

PMID:32383924

Abstract

The density of liquid iron has been determined up to 116 GPa and 4350 K via static compression experiments following an innovative analysis of diffuse scattering from liquid. The longitudinal sound velocity was also obtained to 45 GPa and 2700 K based on inelastic x-ray scattering measurements. Combining these results with previous shock-wave data, we determine a thermal equation of state for liquid iron. It indicates that Earth's outer core exhibits 7.5%-7.6% density deficit, 3.7%-4.4% velocity excess, and an almost identical adiabatic bulk modulus, with respect to liquid iron.

摘要

通过对液体漫散射的创新分析，利用静态压缩实验测定了液态铁在高达116吉帕斯卡和4350开尔文温度下的密度。基于非弹性X射线散射测量，还获得了液态铁在45吉帕斯卡和2700开尔文温度下的纵向声速。将这些结果与先前的冲击波数据相结合，我们确定了液态铁的热状态方程。结果表明，相对于液态铁，地球外核的密度亏损为7.5%-7.6%，速度过剩为3.7%-4.4%，绝热体积模量几乎相同。