In situ high-pressure study of FeP: Implications for planetary cores

被引：24

作者：

Gu, Tingting ^{[1
,2
]}

Wu, Xiang ^{[1
,2
]}

Qin, Shan ^{[1
,2
]}

Dubrovinsky, Leonid ^{[3
]}

机构：

[1] Peking Univ, MOE, Key Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China

[2] Peking Univ, Sch Earth & Space Sci, Beijing 100871, Peoples R China

[3] Univ Bayreuth, Bayer Geoinst, D-95440 Bayreuth, Germany

来源：

PHYSICS OF THE EARTH AND PLANETARY INTERIORS | 2011年 / 184卷 / 3-4期

基金：

中国国家自然科学基金;

关键词：

Light element; Planetary cores; MnP-type structure; High pressure; X-ray diffraction; Mossbauer spectroscopy; EQUATION-OF-STATE; HIGH-TEMPERATURE; INTERNAL STRUCTURE; ELECTRONIC STATES; CRYSTAL-STRUCTURE; EARTHS CORE; PHASE; IRON; DENSITY; MARS;

D O I：

10.1016/j.pepi.2010.11.004

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

with MnP-type structure is isostructural with high-pressure FeS polymorphs (both post-troilite FeS and FeS VI), which are believed to exist in planetary cores. Due to similar PTX phase diagrams of binary Fe-P and Fe-S, phosphorus can incorporate with iron-sulfur at planetary core conditions. To understand such substitution and the high-pressure behavior of FeP, we investigate the structural stability of FeP up to 15.6 GPa and 1800 +/- 200 K by combined in situ powder X-ray diffraction and Mossbauer spectroscopy. Our experimental results show that FeP remains the MnP-type structure throughout the PT range covered. Isothermal equation of state of FeP is obtained with V-0 of 92.91(8)angstrom(3), B-0 of 205(7) GPa, and B'(0) of 4. The shortest axis of the MnP-type FeP cell, the b-axis, is the most compressible, due to the soft edge-sharing octahedra along the b-axis. Mossbauer results show that no electronic structure changes occur up to 15.6 GPa, but indicate decreasing distortion of FeP6 octahedron with pressure increasing. The behavior of FeP is quite different from that of FeS under high pressure and high temperature, suggesting that phosphorus will have a significant impact on stability and electronic properties of FeS within terrestrial planet cores. Crown Copyright (C) 2010 Published by Elsevier By. All rights reserved.

引用

页码：154 / 159

页数：6

共 68 条

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