Density of Fe-3.5 wt% C liquid at high pressure and temperature and the effect of carbon on the density of the molten iron

作者：Shimoyama Yuta^*; Terasaki Hidenori; Ohtani Eiji; Urakawa Satoru; Takubo Yusaku; Nishida Keisuke; Suzuki Akio; Katayama Yoshinori

来源：Physics of the Earth and Planetary Interiors, 2013, 224: 77-82.

DOI：10.1016/j.pepi.2013.08.003

• Density
• Fe alloy liquid
• Core
• High pressure

Carbon is a plausible light element candidate in the Earth%26apos;s outer core. We measured the density of liquid Fe-3.5 wt% C up to 6.8 GPa and 2200 K using an X-ray absorption method. The compression curve of liquid Fe-C was fitted using the third-order Birch-Murnaghan equation of state. The bulk modulus and its pressure derivative are K-0.1500K = 55.3 +/- 2.5 GPa and (dK(o)/dP)(T) = 5.2 +/- 1.5, and the thermal expansion coefficient is alpha = 0.86 +/- 0.04 x 10(-4) K-1. The Fe-C density abruptly increases at pressures between 4.3 and 5.5 GPa in the range of present temperatures. Compared with the results of previous density measurements of liquid Fe-C, the effect of carbon on the density of liquid Fe shows a nonideal mixing behavior. The abrupt density increase and nonideal mixing behavior are important factors in determining the light element content in the Earth%26apos;s core.

• 出版日期2013-11