Spin Crossover in Ferropericlase at High Pressure: A Seismologically Transparent Transition?

被引：94

作者：

Antonangeli, Daniele ^{[1
,2
]}

Siebert, Julien ^{[1
,2
]}

Aracne, Chantel M. ^{[2
]}

Farber, Daniel L. ^{[2
,3
]}

Bosak, A. ^{[4
]}

Hoesch, M. ^{[4
]}

Krisch, M. ^{[4
]}

Ryerson, Frederick J. ^{[2
]}

Fiquet, Guillaume ^{[1
]}

Badro, James ^{[1
,2
]}

机构：

[1] Univ Paris Diderot, Univ Paris 06, Inst Phys Globe Paris, Inst Mineral & Phys Milieux Condenses,CNRS,UMR 75, F-75005 Paris, France

[2] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA

[3] Univ Calif Santa Cruz, Dept Earth & Planetary Sci, Santa Cruz, CA 95064 USA

[4] European Synchrotron Radiat Facil, F-38043 Grenoble, France

来源：

SCIENCE | 2011年 / 331卷 / 6013期

基金：

欧洲研究理事会;

关键词：

EARTHS LOWER MANTLE; MGSIO3; PEROVSKITE; SOUND-VELOCITY; IRON; ELASTICITY; (MG; FE)O; MAGNESIOWUSTITE; ANISOTROPY;

D O I：

10.1126/science.1198429

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Seismic discontinuities in Earth typically arise from structural, chemical, or temperature variations with increasing depth. The pressure-induced iron spin state transition in the lower mantle may influence seismic wave velocities by changing the elasticity of iron-bearing minerals, but no seismological evidence of an anomaly exists. Inelastic x-ray scattering measurements on (Mg0.83Fe0.17)O-ferropericlase at pressures across the spin transition show effects limited to the only shear moduli of the elastic tensor. This explains the absence of deviation in the aggregate seismic velocities and, thus, the lack of a one-dimensional seismic signature of the spin crossover. The spin state transition does, however, influence shear anisotropy of ferropericlase and should contribute to the seismic shear wave anisotropy of the lower mantle.

引用

页码：64 / 67

页数：4

共 33 条

[1] Aggregate and single-crystalline elasticity of hcp cobalt at high pressure [J].