| Инд. авторы: | Mashino I., Ohtani E., Hirao N., Mitsui T., Masuda R., Seto M., Sakai T., Takahashi S., Nakano S. |
| Заглавие: | Chemistry and mineralogy of earth's mantle. the spin state of iron in Fe3+-bearing Mg-perovskite and its crystal chemistry at high pressure |
| Библ. ссылка: | Mashino I., Ohtani E., Hirao N., Mitsui T., Masuda R., Seto M., Sakai T., Takahashi S., Nakano S. Chemistry and mineralogy of earth's mantle. the spin state of iron in Fe3+-bearing Mg-perovskite and its crystal chemistry at high pressure // American Mineralogist. - 2014. - Vol.99. - Iss. 8-9. - P.1555-1561. - ISSN 0003-004X. - EISSN 1945-3027. |
| Внешние системы: | DOI: 10.2138/am.2014.4659; РИНЦ: 23988134; SCOPUS: 2-s2.0-84906991203; WoS: 000340580500005; |
| Реферат: | eng: Valence, spin states, and crystallographic sites of Fe in (Mg,Fe)SiO3perovskite were investigated using energy-domain 57Fe-synchrotron Mössbauer 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 Mössbauer 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. © 2014 by Walter de Gruyter Berlin/Boston.
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| Ключевые слова: | substitution; silica; perovskite; Mossbauer spectroscopy; mineralogy; mantle chemistry; manganese; iron; high pressure; crystal chemistry; X-ray diffraction; spin state; Perovskite; Mössbauer spectroscopy; ferric iron; X-ray diffraction; |
| Издано: | 2014 |
| Физ. характеристика: | с.1555-1561 |