FastFind »   Lastname: doi:10.1029/ Year: | Advanced Search  

AGU: Geophysical Research Letters

 

Keywords

  • spin transition
  • equation of state
  • density of the lower mantle

Index Terms

  • Mineralogy and Petrology: Mineral and crystal chemistry
  • Mineral Physics: Equations of state
  • Mineral Physics: Electrical properties
  • Mineral Physics: High-pressure behavior
  • Mineral Physics: X-ray, neutron, and electron spectroscopy and diffraction

Abstract

Spin transition and equations of state of (Mg, Fe)O solid solutions

Yingwei Fei

Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., USA

Li Zhang

Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., USA

Alexandre Corgne

Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., USA

Heather Watson

Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., USA

Angele Ricolleau

Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., USA

Yue Meng

High Pressure Collaborative Access Team, Carnegie Institution of Washington, Argonne, Illinois, USA

Vitali Prakapenka

GeoSoilEnviroCARS, University of Chicago, Argonne, Illinois, USA

We have performed a series of experiments to investigate the compositional effect on the compression behavior of (Mg, Fe)O solid solutions at high pressure. The in-situ synchrotron X-ray diffraction data revealed abnormal volume contractions at about 40, 60, and 80 GPa for (Mg0.80, Fe0.20)O, (Mg0.61, Fe0.39)O, and (Mg0.42, Fe0.58)O, respectively. The volume contractions are associated with the reported electronic transition of high-spin to low-spin in Fe2+, and caused by the reduction of Fe2+ ionic radius across the transition. A least-squares fit of the compression data to the Birch-Murnaghan equation of state yielded bulk modulus K 0 (GPa) = 160 − 10X FeO for the high-spin (Mg,Fe)O and K 0 = 170(3) GPa for the low-spin (Mg,Fe)O. The equations of state of (Mg,Fe)O established in this study are directly applicable to the Earth's lower mantle in composition and pressure ranges and provide essential data for modeling the density profile of the lower mantle.

Received 24 May 2007; accepted 8 August 2007; published 15 September 2007.

Citation: Fei, Y., L. Zhang, A. Corgne, H. Watson, A. Ricolleau, Y. Meng, and V. Prakapenka (2007), Spin transition and equations of state of (Mg, Fe)O solid solutions, Geophys. Res. Lett., 34, L17307, doi:10.1029/2007GL030712.

Cited By

Please wait one moment ...