Phase Stability and Thermal Equation of State of Iron Carbide Fe3C to 245 GPa

被引：5
作者：
Hu, Xiaojun [1 ]
Fei, Yingwei [2 ]
Yang, Jing [2 ]
Cai, Yang [3 ]
Ye, Shijia [3 ]
Qi, Meilan [1 ]
Liu, Fusheng [4 ]
Zhang, Mingjian [4 ]
机构：
[1] Wuhan Univ Technol, Sch Sci, Wuhan, Hubei, Peoples R China
[2] Carnegie Inst Sci, Geophys Lab, Washington, DC 20005 USA
[3] Peac Inst Multiscale Sci, Chengdu, Sichuan, Peoples R China
[4] Southwest Jiaotong Univ, Sch Phys Sci & Technol, Chengdu, Sichuan, Peoples R China
来源：
GEOPHYSICAL RESEARCH LETTERS | 2019年 / 46卷 / 20期
基金：
美国国家科学基金会; 中国国家自然科学基金;
关键词：
Earth core; shockwave compression; iron carbide; core density; core composition; HIGH-PRESSURE; HIGH-TEMPERATURE; SOUND-VELOCITY; CARBON CONTENT; EARTHS CORE; FE7C3; COMPRESSION; CONSTRAINTS; ELASTICITY; SYSTEM;
D O I：
10.1029/2019GL084545
中图分类号：
P [天文学、地球科学];
学科分类号：
07 ;
摘要：
We conducted shock wave experiments on iron carbide Fe3C up to a Hugoniot pressure of 245 GPa. The correlation between the particle velocity (u(p)) and shock wave velocity (u(s)) can be fitted into a linear relationship, u(s) = 4.627(+/- 0.073) + 1.614(+/- 0.028) u(p). The density-pressure relationship is consistent with a single-phase compression without decomposition. The inference is further supported by the comparison of the observed Hugoniot density with the calculated Hugoniot curves of possible decomposition products. The new Hugoniot data combined with the reported 300-K isothermal compression data yielded a Gruneisen parameter of gamma = 2.23(7.982/rho)(0.29). The thermal equation of state of Fe3C is further used to calculate the density profile of Fe3C along the Earth's adiabatic geotherm. The density of Fe3C was found to be too low (by similar to 5%) to match the observed density in the Earth's inner core, and Fe3C is unlikely a dominant component of the inner core.
引用
收藏
页码：11018 / 11024
页数：7
相关论文
共 37 条
[1]  
Bazhanova Z.G., 2012, PHYS-USP, V182, P521
[2]   Hugoniot data for iron [J].
Brown, JM ;
Fritz, JN ;
Hixson, RS .
JOURNAL OF APPLIED PHYSICS, 2000, 88 (09) :5496-5498
[3]   PHASE-TRANSITIONS, GRUNEISEN-PARAMETER, AND ELASTICITY FOR SHOCKED IRON BETWEEN 77-GPA AND 400-GPA [J].
BROWN, JM ;
MCQUEEN, RG .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS, 1986, 91 (B7) :7485-7494
[4]   Experimental constraints on the sound velocities of cementite Fe3C to core pressures [J].
Chen, Bin ;
Lai, Xiaojing ;
Li, Jie ;
Liu, Jiachao ;
Zhao, Jiyong ;
Bi, Wenli ;
Alp, E. Ercan ;
Hu, Michael Y. ;
Xiao, Yuming .
EARTH AND PLANETARY SCIENCE LETTERS, 2018, 494 :164-171
[5]   Hidden carbon in Earth's inner core revealed by shear softening in dense Fe7C3 [J].
Chen, Bin ;
Li, Zeyu ;
Zhang, Dongzhou ;
Liu, Jiachao ;
Hu, Michael Y. ;
Zhao, Jiyong ;
Bi, Wenli ;
Alp, E. Ercan ;
Xiao, Yuming ;
Chow, Paul ;
Li, Jie .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2014, 111 (50) :17755-17758
[6]   Magneto-elastic coupling in compressed Fe7C3 supports carbon in Earth's inner core [J].
Chen, Bin ;
Gao, Lili ;
Lavina, Barbara ;
Dera, Przemyslaw ;
Alp, Esen E. ;
Zhao, Jiyong ;
Li, Jie .
GEOPHYSICAL RESEARCH LETTERS, 2012, 39
[7]   Carbon solubility in core melts in a shallow magma ocean environment and distribution of carbon between the Earth's core and the mantle [J].
Dasgupta, Rajdeep ;
Walker, David .
GEOCHIMICA ET COSMOCHIMICA ACTA, 2008, 72 (18) :4627-4641
[8]   PRELIMINARY REFERENCE EARTH MODEL [J].
DZIEWONSKI, AM ;
ANDERSON, DL .
PHYSICS OF THE EARTH AND PLANETARY INTERIORS, 1981, 25 (04) :297-356
[9]   Thermal equation of state of hcp-iron: Constraint on the density deficit of Earth's solid inner core [J].
Fei, Yingwei ;
Murphy, Caitlin ;
Shibazaki, Yuki ;
Shahar, Anat ;
Huang, Haijun .
GEOPHYSICAL RESEARCH LETTERS, 2016, 43 (13) :6837-6843
[10]   Experimental study and thermodynamic calculations of phase relations in the Fe-C system at high pressure [J].
Fei, Yingwei ;
Brosh, Eli .
EARTH AND PLANETARY SCIENCE LETTERS, 2014, 408 :155-162
1234