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Behavior of iron in (Mg,Fe)SiO_3 post-perovskite assemblages at Mbar pressures

Jackson, Jennifer M. and Sturhahn, Wolfgang and Tschauner, Oliver and Lerche, Michael and Fei, Yingwei (2009) Behavior of iron in (Mg,Fe)SiO_3 post-perovskite assemblages at Mbar pressures. Geophysical Research Letters, 36 . rt. No. L10301. ISSN 0094-8276. https://resolver.caltech.edu/CaltechAUTHORS:20090713-085032457

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Abstract

The electronic environment of the iron sites in post-perovskite (PPv) structured (^(57)Fe,Mg)SiO_3 has been measured in-situ at 1.12 and 1.19 Mbar at room temperature using ^(57)Fe synchrotron Mössbauer spectroscopy. Evaluation of the time spectra reveals two distinct iron sites, which are well distinguished by their hyperfine fields. The dominant site is consistent with an Fe^(3+)-like site in a high spin state. The second site is characterized by a small negative isomer shift with respect to α-iron and no quadrupole splitting, consistent with a metallic iron phase. Combined with SEM/EDS analyses of the quenched assemblage, our results are consistent with the presence of a metallic iron phase co-existing with a ferric-rich PPv. Such a reaction pathway may aid in our understanding of the chemical evolution of Earth's core-mantle-boundary region.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1029/2009GL037815DOIArticle
http://www.agu.org/pubs/crossref/2009/2009GL037815.shtmlPublisherArticle
ORCID:
AuthorORCID
Jackson, Jennifer M.0000-0002-8256-6336
Sturhahn, Wolfgang0000-0002-9606-4740
Tschauner, Oliver0000-0003-3364-8906
Additional Information:© 2009 American Geophysical Union. Received 18 February 2009; accepted 30 March 2009; published 19 May 2009. We thank J. Zhao for technical assistance, D. Stevenson for discussions, D. Adams and two anonymous reviewers for their comments. Support for this work was provided in part by the National Science Foundation (NSF) EAR 0711542 and Caltech (J.M.J.), NSF-EAR 0552010 and NNSA Cooperative Agreement DOE-FC52-06NA27684 (O.T.), the U.S. DOE, Office of Science, BES under DE-AC02- 06CH11357, and COMPRES under NSF Cooperative Agreement EAR 06-49658. X-ray diffraction experiments were performed at HPCAT (Sector 16, APS). SEM and EDS analyses were carried out at the Caltech GPS Division Analytical Facility (MRSEC Program of the NSF under DMR-0080065).
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
NSFEAR-0711542
CaltechUNSPECIFIED
NSFEAR-0552010
National Nuclear Security Administration (NNSA)DE-FC52-06NA27684
Department of Energy (DOE)DE-AC02-06CH11357
Consortium for Materials Properties Research in Earth Sciences (COMPRES)UNSPECIFIED
NSFEAR-0649658
NSFDMR-0080065
Subject Keywords:post-perovskite; iron; Mössbauer
Record Number:CaltechAUTHORS:20090713-085032457
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20090713-085032457
Official Citation:Jackson, J. M., W. Sturhahn, O. Tschauner, M. Lerche, and Y. Fei (2009), Behavior of iron in (Mg,Fe)SiO3 post-perovskite assemblages at Mbar pressures, Geophys. Res. Lett., 36, L10301, doi:10.1029/2009GL037815.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14566
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:11 Aug 2009 18:39
Last Modified:24 Jan 2020 18:03

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