Behavior of iron in (Mg,Fe)SiO[subscript 3] post-perovskite assemblages at Mbar pressures

Journal Article · Mon Oct 04 04:00:00 EDT 2010 · Geophys. Res. Lett.

DOI:https://doi.org/10.1029/2009GL037815· OSTI ID:1005683

Jackson, Jennifer M; Sturhahn, Wolfgang; Tschauner, Oliver; Lerche, Michael; Fei, Yingwei

The electronic environment of the iron sites in postperovskite (PPv) structured ({sup 57}Fe,Mg)SiO{sub 3} has been measured in-situ at 1.12 and 1.19 Mbar at room temperature using {sup 57}Fe synchrotron Moessbauer 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{sup 3+}-like site in a high spin state. The second site is characterized by a small negative isomer shift with respect to {alpha}-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 coexisting 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.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE
• OSTI ID: 1005683
• Journal Information: Geophys. Res. Lett., Journal Name: Geophys. Res. Lett. Journal Issue: 2009 Vol. 36; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

43 PARTICLE ACCELERATORS
BEHAVIOR
EVALUATION
HIGH SPIN STATES
IRON
ISOMER SHIFT
MOESSBAUER EFFECT
PEROVSKITE
PRESSURE DEPENDENCE
QUADRUPOLES
SPECTRA
SYNCHROTRON RADIATION