@article{331ddc6b5ce846c780696cacbd5ede7c,
title = "Chemistry and mineralogy of earth's mantle. the spin state of iron in Fe3+-bearing Mg-perovskite and its crystal chemistry at high pressure",
abstract = "Valence, spin states, and crystallographic sites of Fe in (Mg,Fe)SiO3perovskite were investigated using energy-domain 57Fe-synchrotron M{\"o}ssbauer spectroscopy and powder X-ray diffraction up to 86 GPa. The volumes of Fe3+-bearing perovskite in this study are slightly smaller than those of Mg endmember perovskite. Our M{\"o}ssbauer data suggest that Fe3+prefers A sites coupled with Mg vacancies, which is consistent with previous data at ambient conditions. Fe3+in the A site remains in a high-spin state up to 86 GPa, and some fraction of the A site is occupied by Fe2+at pressures above 30 GPa. Fe2+in the A sites is also in a high-spin state up to 86 GPa. The coupled substitution from Mg2+to a highspin state of Fe3+and Mg2+vacancy would make the volume of perovskite smaller than that of Mg end-member perovskite. If the lower mantle is saturated in silica, perovskite containing high-spin Fe3+in A site has a higher density. Such silica oversaturated regions could sink by the density difference.",
keywords = "M{\"o}ssbauer spectroscopy, Perovskite, X-ray diffraction, ferric iron, spin state",
author = "Izumi Mashino and Eiji Ohtani and Naohisa Hirao and Takaya Mitsui and Ryo Masuda and Makoto Seto and Takeshi Sakai and Suguru Takahashi and Satoshi Nakano",
note = "Funding Information: We thank M. Akasaka at Shimane University for M{\"o}ssbauer spectroscopy measurement of starting materials and K. Fujino at Ehime University for useful discussions. We also thank S. Kamada, T. Sakamaki, M. Hamada, I. Ohira, N. Nishitani, T. Sakairi, and M. Murakami of Tohoku University for their technical assistance and useful discussions. We also thank B. Mysen of Carnegie Institution of Washington for useful discussion for improving this manuscript. The synchrotron radiation M{\"o}ssbauer spectroscopy measurements were performed at BL11XU in SPring-8 and the compression experiments were performed at BL10XU in SPring-8. This work was supported by JSPS KAKENHI Grant Numbers 18104009 and 22000002 awarded to E.O. This work was also partly supported by the Ministry of education and science of Russian Federation, project no 14.B25.31.0032 awarded to E.O. This work was conducted as part of the Global Center of Excellence program of Tohoku University “Global Education and Research Center for Earth and Planetary Dynamics.” Publisher Copyright: {\textcopyright} 2014 by Walter de Gruyter Berlin/Boston.",
year = "2014",
month = aug,
day = "1",
doi = "10.2138/am.2014.4659",
language = "English",
volume = "99",
pages = "1555--1561",
journal = "American Mineralogist",
issn = "0003-004X",
publisher = "Mineralogical Society of America",
number = "8-9",
}