Iron spin transition in Earth's mantle

Journal Article · Fri Feb 06 00:00:00 EST 2015 · Proc. Natl. Acad. Sci. USA

DOI:https://doi.org/10.1073/pnas.0508919102· OSTI ID:1169972

Speziale, S.; Milner, A.; Lee, V. E.; Clark, S. M.; Pasternak, M. P.; Jeanloz, R. ^[1]

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1. LBNL

High-pressure Mössbauer spectroscopy on several compositions across the (Mg,Fe)O magnesiowüstite solid solution confirms that ferrous iron (Fe²⁺) undergoes a high-spin to low-spin transition at pressures and for compositions relevant to the bulk of the Earth's mantle. High-resolution x-ray diffraction measurements document a volume change of 4–5% across the pressure-induced spin transition, which is thus expected to cause seismological anomalies in the lower mantle. The spin transition can lead to dissociation of Fe-bearing phases such as magnesiowüstite, and it reveals an unexpected richness in mineral properties and phase equilibria for the Earth's deep interior.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: DOE - BASIC ENERGY SCIENCESDOE - OTHERNSFUNIVERSITY
• OSTI ID: 1169972
• Journal Information: Proc. Natl. Acad. Sci. USA, Vol. 102, Issue (50) ; 12, 2005
• Country of Publication: United States
• Language: ENGLISH