Journal ArticleDOI
Crystal structure and thermal expansion of (Mg,Fe)SiO3 perovskite
TLDR
In this paper, high-resolution x-ray diffraction data were collected from 10 to 433K on a homogeneous polycrystalline specimen of Mg{sub 0.9}Fe{ sub 0.1}SiO{sub 3}-perovskite.Abstract:
High-resolution x-ray diffraction data were collected from 10 to 433K on a homogeneous polycrystalline specimen of Mg{sub 0.9}Fe{sub 0.1}SiO{sub 3}-perovskite. Rietveld structural refinement and x-ray absorption fluorescence measurements demonstrate that Fe substitutes for Mg and not Si. The thermal expansion behavior is anisotropic, with the orthorhombic distortion becoming less with increasing temperature. The volumetric thermal expansion, which is dominated by the decrease in octahedral tilts, is 1.9 {times} 10{sup {minus}5} K{sup {minus}1} between 150 and 373K. No evidence of conversion to enstatite could be found up to 873 K.read more
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The core-mantle boundary region
David E. Loper,Thorne Lay +1 more
TL;DR: A recent overview of the progress and future directions in geophysical investigations of the CMB region can be found in this article, where the authors highlight the potential for developing a comprehensive understanding of this region in the next few decades.
Journal ArticleDOI
Thermoelastic properties and crystal structure of MgSiO3 perovskite at lower mantle pressure and temperature conditions
TL;DR: In this article, a new synchrotron X-ray diffraction study of MgSiO3 perovskite at high-pressure and high-temperature has been carried out in a laser-heated diamond-anvil cell to 94 GPa and temperatures above 2500 K.
Journal ArticleDOI
Thermoelastic properties of MgSiO3 perovskite determined by in situ X ray observations up to 30 GPa and 2000 K
TL;DR: In situ X ray experiments on MgSiO3 perovskite at pressures of 21-29 GPa and temperatures of 300-2000 K were carried out using an MA8-type high-pressure apparatus, employing sintered diamond anvils, combined with synchrotron radiation.
Journal ArticleDOI
P-V-T equation of state of (Mg, Fe)SiO3 perovskite: constraints on composition of the lower mantle
TL;DR: In this paper, a combination of X-ray diffraction during heating cycles and Raman spectroscopy on recovered samples was determined under which the P - V - T behavior of the perovskite remains reversible.
Journal ArticleDOI
A synchrotron Mössbauer spectroscopy study of (Mg,Fe)SiO3 perovskite up to 120 GPa
Jennifer M. Jackson,Wolfgang Sturhahn,Guoyin Shen,Jiyong Zhao,Michael Y. Hu,Michael Y. Hu,Daniel Errandonea,Daniel Errandonea,Jay D. Bass,Yingwei Fei +9 more
TL;DR: In this article, the electronic environment of the Fe nuclei in two silicate perovskite samples, Fe_(0.05)Mg/(0.95)SiO_3 (Pv05) and Fe(0.9)Si O_3(Pv10), were measured to 120 GPa and 75 GPa, respectively, at room temperature using diamond anvil cells and synchrotron Mossbauer spectroscopy (SMS).
References
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Journal ArticleDOI
Synthesis and Equation of State of (Mg,Fe) SiO3 Perovskite to Over 100 Gigapascals.
Elise Knittle,Raymond Jeanloz +1 more
TL;DR: It is demonstrated that perovskite can exist throughout the pressure range of the lower mantle and that it is therefore likely to be the most abundant mineral in Earth.
Journal ArticleDOI
Thermal expansion of silicate perovskite and stratification of the Earth's mantle
TL;DR: The thermal expansion coefficient of perovskite provides an important constraint on possible compositional models for the lower mantle as discussed by the authors, which suggests that the upper and lower mantle are chemically distinct.
Journal Article
Perovskite-type MgSiO 3 ; single-crystal X-ray diffraction study
Journal ArticleDOI
The mineralogy and chemistry of the lower mantle: an implication of the ultrahigh-pressure phase relations in the system MgOFeOSiO2
TL;DR: In this paper, phase relations in the system MgOFeOSiO2 have been investigated at GPa and 1600°C with a uniaxial split-sphere-type apparatus.
Journal ArticleDOI
Single crystal X-ray diffraction study of MgSiO3 perovskite from 77 to 400 K
Nancy L. Ross,Robert M. Hazen +1 more
TL;DR: In this article, a single crystal X-ray diffraction study of MgSiO3 perovskite has been conducted from 77 to 400 K. The thermal expansion coefficient between 298 and 381 K is 2.2(8) × 10-5 K-1.