气候变化领域集成服务门户(CCPortal): Eutectic melting of Fe-3 at% Si-4 at% C up to 200 GPa and implications for the Earth's core

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DOI	10.1016/j.epsl.2020.116382
	Eutectic melting of Fe-3 at% Si-4 at% C up to 200 GPa and implications for the Earth's core
	Miozzi F.; Morard G.; Antonangeli D.; Baron M.A.; Boccato S.; Pakhomova A.; Garbarino G.; Mezouar M.; Fiquet G.
发表日期	2020
ISSN	0012821X
卷号	544
英文摘要	Properties of the Fe-Si and Fe-C binary systems have been shown unable to satisfy the geophysical and petrological constraints of the Earth's core (i.e. velocities, densities, melting temperature) if only Si or C were to be incorporated as light element. Recent ab initio calculations suggest on the contrary that density, compressional and shear sound velocities, as well as the Poisson's ratio of the inner core could be matched by an hcp-Fe alloy containing Si and C. The combined effect of the two elements in a ternary Fe-Si-C system has never been experimentally investigated under high pressure. We thus studied the melting curve and the phase relations of the ternary iron-silicon-carbon system by in situ X-ray diffraction at high pressures and high temperatures. Starting with a low light element content (4 at% C-3 at% Si), a stable assemblage made of hcp Fe (+Si, +C) and Fe3C is observed up to 200 GPa. Fe can incorporate both Si and C in its hexagonal structure, with the latter strongly affecting the volume and the melting temperature. While the presence of a third light element is likely necessary, we here document that the effect of C in lowering the melting temperature of Fe-Si, is large enough to possibly keep the core-mantle boundary temperature below the solidus of the mantle silicates. © 2020 Elsevier B.V.
关键词	carbon core high pressure light elements melting silicon
英文关键词	Acoustic wave velocity; Calculations; High pressure effects; Iron alloys; Melting point; Shear flow; Silicates; Ab initio calculations; Combined effect; Core-mantle boundary; Eutectic melting; Hexagonal structures; High temperature; In-situ X-ray diffraction; Shear sound velocities; Silicon; carbon; core (planetary); core-mantle boundary; Earth structure; iron; melting; P-T conditions; petrology; silicate; silicon
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202790
作者单位	Sorbonne Université, UMR CNRS 7590, Muséum National d'Histoire Naturelle, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris, 75005, France; Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany; European Synchrotron Radiation Facility (ESRF), Grenoble, France
推荐引用方式 GB/T 7714	Miozzi F.,Morard G.,Antonangeli D.,et al. Eutectic melting of Fe-3 at% Si-4 at% C up to 200 GPa and implications for the Earth's core[J],2020,544.
APA	Miozzi F..,Morard G..,Antonangeli D..,Baron M.A..,Boccato S..,...&Fiquet G..(2020).Eutectic melting of Fe-3 at% Si-4 at% C up to 200 GPa and implications for the Earth's core.Earth and Planetary Science Letters,544.
MLA	Miozzi F.,et al."Eutectic melting of Fe-3 at% Si-4 at% C up to 200 GPa and implications for the Earth's core".Earth and Planetary Science Letters 544(2020).