|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ЦЭМИ РАН |
||
Chromium solubility in perovskite at high pressure: the structure of (Mg1–xCrx)(Si1–xCrx)O3 (with x = 0.07) synthesized at 23 GPa and 1600°Cстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 21 июля 2014 г.
- Авторы: Bindi L., Sirotkina E.A., Bobrov A.V., Irifune T.
- Журнал: American Mineralogist
- Том: 99
- Год издания: 2014
- Издательство: Mineralogical Society of America
- Местоположение издательства: United States
- Первая страница: 866
- Последняя страница: 869
- DOI: 10.2138/am.2014.4784
- Аннотация: The crystal structure and chemical composition of a crystal of (Mg1–xCrx)(Si1–xCrx)O3 perovskite (with x = 0.07) synthesized in the model system Mg3Cr2Si3O12–Mg4Si4O12 at 23 GPa and 1600 °C have been investigated. The compound was found to be orthorhombic, space group Pbnm, with lattice parameters a = 4.8213(5), b = 4.9368(6), c = 6.9132(8) Å, V = 164.55(3) Å3. The structure was refined to R = 0.046 using 473 independent reflections. Chromium was found to substitute for both Mg at the dodecahedral X site (with a mean bond distance of 2.187 Å) and Si at the octahedral Y site (mean: 1.814 Å), according to the reaction Mg2+ + Si4+ = 2Cr3+. Such substitutions cause a shortening of the <X-O> and a lengthening of the <Y-O> distances with respect to the values typically observed for pure MgSiO3 perovskite. Although high Cr-contents are not considered in the pyrolite model, Cr-bearing perovskite may be an important host for chromium in the lower mantle. The successful synthesis of perovskite with high-Cr content and its structural characterization are of key importance because the study of its thermodynamic constants combined with the data on phase relations in the lower-mantle systems can provide new constraints on thermobarometry of perovskite-bearing assemblages.
- Добавил в систему: Бобров Андрей Викторович