Solid solution behaviour of CaSiO3 and MgSiO3 perovskites
نویسندگان
چکیده
منابع مشابه
Cation sites in Al-rich MgSiO3 perovskites
Local structure analysis of Al-containing magnesium silicate perovskite has been carried out with X-ray absorption spectra recorded at the Mg, Al, and Si K-edges using the SA32 beam-line of SuperAco (Orsay, France). The Al-XAFS spectrum of (MgSi)0.85Al0.3O3 perovskite (synthesized in a multi-anvil apparatus) cannot be explained by assuming that Al31 occurs in octahedral or dodecahedral sites on...
متن کاملTheoretical determination of the structures of CaSiO3 perovskites.
Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discusse...
متن کاملPrediction of a hexagonal SiO2 phase affecting stabilities of MgSiO3 and CaSiO3 at multimegabar pressures.
Ultrahigh-pressure phase relationship of SiO(2) silica in multimegabar pressure condition is still quite unclear. Here, we report a theoretical prediction on a previously uncharacterized stable structure of silica with an unexpected hexagonal Fe(2)P-type form. This phase, more stable than the cotunnite-type structure, a previously postulated postpyrite phase, was discovered to stabilize at 640 ...
متن کاملElastic Behavior and Properties of CaSiO3 Wollastonite and Perovskites to 15 GPa and 1200K
Introduction Seismological observations provide information about the properties and processes of the Earth’s interior in the form of profiles of density and velocity as a function of depth. Seismic tomography on a global scale reveals lateral variations in compressional (P) and shear (S) wave velocities and densities at various depths of the Earth’s interior, reflecting differences in chemical...
متن کاملMelting phase relations in the MgSiO3–CaSiO3 system at 24 GPa
The Earth’s lower mantle is composed of bridgmanite, ferropericlase, and CaSiO3-rich perovskite. The melting phase relations between each component are key to understanding the melting of the Earth’s lower mantle and the crystallization of the deep magma ocean. In this study, melting phase relations in the MgSiO3–CaSiO3 system were investigated at 24 GPa using a multi-anvil apparatus. The eutec...
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ژورنال
عنوان ژورنال: Physics and Chemistry of Minerals
سال: 2010
ISSN: 0342-1791,1432-2021
DOI: 10.1007/s00269-010-0405-0