Phase transition of FeO and stratification in earth's outer core

Haruka Ozawa, Futoshi Takahashi, Kei Hirose, Yasuo Ohishi, Naohisa Hirao

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Light elements such as oxygen in Earth's core influence the physical properties of the iron alloys that exist in this region. Describing the high-pressure behavior of these materials at core conditions constrains models of core structure and dynamics. From x-ray diffraction measurements of iron monoxide (FeO) at high pressure and temperature, we show that sodium chloride (NaCl)-type (B1) FeO transforms to a cesium chloride (CsCl)-type (B2) phase above 240 gigapascals at 4000 kelvin with 2% density increase. The oxygen-bearing liquid in the middle of the outer core therefore has a modified Fe-O bonding environment that, according to our numerical simulations, suppresses convection. The phase-induced stratification is seismologically invisible but strongly affects the geodynamo.

Original languageEnglish
Pages (from-to)792-794
Number of pages3
JournalScience
Volume334
Issue number6057
DOIs
Publication statusPublished - Nov 11 2011
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Medicine(all)
  • General

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