气候变化领域集成服务门户(CCPortal): High-Pressure Deformation of Iron–Nickel–Silicon Alloys and Implications for Earth’s Inner Core

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DOI	10.1029/2020JB021077
	High-Pressure Deformation of Iron–Nickel–Silicon Alloys and Implications for Earth’s Inner Core
	Brennan M.C.; Fischer R.A.; Couper S.; Miyagi L.; Antonangeli D.; Morard G.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	Earth’s inner core exhibits strong seismic anisotropy, often attributed to the alignment of hexagonal close-packed iron (hcp-Fe) alloy crystallites with the Earth’s poles. How this alignment developed depends on material properties of the alloy and is important to our understanding of the core’s crystallization history and active geodynamical forcing. Previous studies suggested that hcp-Fe is weak under deep Earth conditions but did not investigate the effects of the lighter elements known to be part of the inner core alloy. Here, we present results from radial X-ray diffraction experiments in a diamond anvil cell that constrain the strength and deformation properties of iron-nickel-silicon (Fe–Ni–Si) alloys up to 60 GPa. We also show the results of laser heating to 1650 K to evaluate the effect of temperature. Observed alloy textures suggest different relative activities of the various hcp deformation mechanisms compared to pure Fe, but these textures could still account for the theorized polar alignment. Fe–Ni–Si alloys are mechanically stronger than Fe and Fe–Ni; extrapolated to inner core conditions, Si-bearing alloys may be more than an order of magnitude stronger. This enhanced strength proportionally reduces the effectivity of dislocation creep as a deformation mechanism, which may suggest that texture developed during crystallization rather than as the result of postsolidification plastic flow. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	inner core; iron-nickel-silicon alloy; seismic anisotropy
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187306
作者单位	Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, United States; Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, United States; Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie(IMPMC), Paris, France; Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, Université Gustave Eiffel, ISTerre, Gières, France
推荐引用方式 GB/T 7714	Brennan M.C.,Fischer R.A.,Couper S.,等. High-Pressure Deformation of Iron–Nickel–Silicon Alloys and Implications for Earth’s Inner Core[J],2021,126(3).
APA	Brennan M.C.,Fischer R.A.,Couper S.,Miyagi L.,Antonangeli D.,&Morard G..(2021).High-Pressure Deformation of Iron–Nickel–Silicon Alloys and Implications for Earth’s Inner Core.Journal of Geophysical Research: Solid Earth,126(3).
MLA	Brennan M.C.,et al."High-Pressure Deformation of Iron–Nickel–Silicon Alloys and Implications for Earth’s Inner Core".Journal of Geophysical Research: Solid Earth 126.3(2021).