Electronic spin transitions in iron-bearing MgSiO3 perovskite

被引:82
作者
Stackhouse, Stephen [1 ]
Brodholt, John P. [1 ]
Price, G. David [1 ]
机构
[1] UCL, Dept Earth Sci, London WC1E 6BT, England
基金
英国自然环境研究理事会;
关键词
ab initio; iron; perovskite; spin transitions; elastic properties; lower mantle;
D O I
10.1016/j.epsl.2006.10.035
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
The electronic spin state of iron in perovskites with the chemical composition Mg0.9375Fe0.0625SiO3, Mg0.8750Fe0.1250SiO3 and Mg0.9375Fe0.0625Si0.9375Fe0.0625O3, have been determined at 0 K and various pressures between 40-160 GPa, using ab initio methods. The results indicate that ferric iron exhibits a wide range of spin transition pressures between about 60-160 GPa, while ferrous iron has a much narrower span, between about 130-145 GPa. In general, the lowest spin transition pressures are associated with the most energetically favorable substitution configurations, where iron atoms are closest together. The effect of spin state on calculated elastic properties is found to be small. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码:282 / 290
页数:9
相关论文
共 48 条
[1]   Electronic structure of the antiferromagnetic B1-structured FeO -: art. no. 165111 [J].
Alfredsson, M ;
Price, GD ;
Catlow, CRA ;
Parker, SC ;
Orlando, R ;
Brodholt, JP .
PHYSICAL REVIEW B, 2004, 70 (16) :1-6
[2]   BAND THEORY AND MOTT INSULATORS - HUBBARD-U INSTEAD OF STONER-I [J].
ANISIMOV, VI ;
ZAANEN, J ;
ANDERSEN, OK .
PHYSICAL REVIEW B, 1991, 44 (03) :943-954
[3]   Thermochemical state of the lower mantle: New insights from mineral physics [J].
Badro, J ;
Fiquet, G ;
Guyot, F .
EARTH'S DEEP MANTLE: STRUCTURE, COMPOSITION, AND EVOLUTION, 2005, 160 :241-260
[4]   Iron partitioning in Earth's mantle:: Toward a deep lower mantle discontinuity [J].
Badro, J ;
Fiquet, G ;
Guyot, F ;
Rueff, JP ;
Struzhkin, VV ;
Vankó, G ;
Monaco, G .
SCIENCE, 2003, 300 (5620) :789-791
[5]   Electronic transitions in perovskite:: Possible nonconvecting layers in the lower mantle [J].
Badro, J ;
Rueff, JP ;
Vankó, G ;
Monaco, G ;
Fiquet, G ;
Guyot, F .
SCIENCE, 2004, 305 (5682) :383-386
[6]   PROJECTOR AUGMENTED-WAVE METHOD [J].
BLOCHL, PE .
PHYSICAL REVIEW B, 1994, 50 (24) :17953-17979
[7]   Effect of chemistry on the stability and elasticity of the perovskite and post-perovskite phases in the MgSiO3-FeSiO3-Al2O3 system and implications for the lowermost mantle -: art. no. L16310 [J].
Caracas, R ;
Cohen, RE .
GEOPHYSICAL RESEARCH LETTERS, 2005, 32 (16) :1-4
[8]   GROUND-STATE OF THE ELECTRON-GAS BY A STOCHASTIC METHOD [J].
CEPERLEY, DM ;
ALDER, BJ .
PHYSICAL REVIEW LETTERS, 1980, 45 (07) :566-569
[9]   Structural, electronic, and magnetic properties of Fe2SiO4 fayalite:: Comparison of LDA and GGA results -: art. no. 094106 [J].
Cococcioni, M ;
Dal Corso, A ;
de Gironcoli, S .
PHYSICAL REVIEW B, 2003, 67 (09) :941061-941067
[10]   Magnetic collapse in transition metal oxides at high pressure: Implications for the Earth [J].
Cohen, RE ;
Mazin, II ;
Isaak, DG .
SCIENCE, 1997, 275 (5300) :654-657