Stability and compressibility of a new iron-nitride -Fe7N3 to core pressures

被引：41

作者：

Minobe, Sayuri ^{[1
]}

Nakajima, Yoichi ^{[2
]}

Hirose, Kei ^{[3
,4
]}

Ohishi, Yasuo ^{[5
]}

机构：

[1] Tokyo Inst Technol, Dept Earth & Planetary Sci, Tokyo 152, Japan

[2] RIKEN, RIKEN SPring Ctr 8, Mat Dynam Lab, Sayo, Japan

[3] Tokyo Inst Technol, Earth Life Sci Inst, Tokyo 152, Japan

[4] Japan Agcy Marine Earth Sci & Technol, Lab Ocean Earth Life Evolut Res, Yokosuka, Kanagawa, Japan

[5] Japan Synchrotron Radiat Res Inst, Sayo, Japan

来源：

GEOPHYSICAL RESEARCH LETTERS | 2015年 / 42卷 / 13期

关键词：

nitrogen; iron nitride; core; phase transition; high pressure; EARTHS INNER-CORE; X-RAY-DIFFRACTION; FE-C SYSTEM; NITROGEN SOLUBILITY; OXYGEN FUGACITY; ALPHA-IRON; CARBON; TEMPERATURE; FE7C3; CARBIDE;

D O I：

10.1002/2015GL064496

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

We have examined the phase relations in the iron-rich portion of the Fe-N binary system up to 150GPa and 2720K in a laser-heated diamond anvil cell. Synchrotron X-ray diffraction measurements revealed the formation of a new phase (-Fe7N3) above 41GPa and similar to 1000K. The phase is structurally identical or very close to Fe7C3 and the most iron-rich Fe-N intermediate compound at its stability field. We also measured the volume of -Fe7N3 to 132GPa and found its elastic property very similar to that of Fe7C3. Recently, it has been proposed that the density and sound velocities, in particular, shear wave velocity, in the Earth's inner core are reconciled with Fe7C3, but such properties could be explained by -Fe7N3 equally well. It is therefore possible that the inner core consists of Fe-7(C,N)(3), which is found as diamond inclusions and likely stable under inner core conditions.

引用

页码：5206 / 5211

页数：6

共 38 条

[1] A high-pressure X-ray diffraction study of iron nitrides: Implications for Earth's core [J].

Adler, JF ;

Williams, Q .

JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 2005, 110 (B1) :1-11

[2] 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

[3] 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

[4] Ingassing, Storage, and Outgassing of Terrestrial Carbon through Geologic Time [J].

Dasgupta, Rajdeep .

CARBON IN EARTH, 2013, 75 :183-229

[5] High-pressure high-temperature equation of state of KCl and KBr [J].

Dewaele, A. ;

Belonoshko, A. B. ;

Garbarino, G. ;

Occelli, F. ;

Bouvier, P. ;

Hanfland, M. ;

Mezouar, M. .

PHYSICAL REVIEW B, 2012, 85 (21)

[6] Quasihydrostatic equation of state of iron above 2 Mbar [J].

Dewaele, Agnes ;

Loubeyre, Paul ;

Occelli, Florent ;

Mezouar, Mohamed ;

Dorogokupets, Peter I. ;

Torrent, Marc .

PHYSICAL REVIEW LETTERS, 2006, 97 (21)

[7]

FASISKA EJ, 1967, T METALL SOC AIME, V239, P1818

[8] 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

[9] Melting of the Earth's inner core [J].

Gubbins, David ;

Sreenivasan, Binod ;

Mound, Jon ;

Rost, Sebastian .

NATURE, 2011, 473 (7347) :361-U53

[10] High pressure high-temperature behavior and magnetic properties of Fe4N: experiment and theory [J].

Guo, Kai ;

Rau, Dieter ;

von Appen, Joerg ;

Prots, Yurii ;

Schnelle, Walter ;

Dronskowski, Richard ;

Niewa, Rainer ;

Schwarz, Ulrich .

HIGH PRESSURE RESEARCH, 2013, 33 (03) :684-696

← 1 2 3 4 →