气候变化领域集成服务门户(CCPortal): High-Pressure Phase Stability and Thermoelastic Properties of Iron Carbonitrides and Nitrogen in the Deep Earth

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DOI	10.1029/2021JB021934
	High-Pressure Phase Stability and Thermoelastic Properties of Iron Carbonitrides and Nitrogen in the Deep Earth
	Huang S.; Wu X.; Zhu F.; Lai X.; Li J.; Neill O.K.; Qin S.; Rapp R.; Zhang D.; Dera P.; Chariton S.; Prakapenka V.B.; Chen B.
发表日期	2021
ISSN	21699313
卷号	126 期号:6
英文摘要	Iron-dominant metallic phases are likely the primary hosts for nitrogen in the reduced deep Earth, hence the storage of nitrogen in the lower mantle and the core is governed by the behavior of the Fe-N-C system at high temperatures and pressures. In this study, phase transitions and thermoelastic properties of iron carbonitrides were investigated at high pressure-temperature conditions by diamond anvil cell experiments and first-principles calculations. Experimental data revealed no phase transition in ε-type Fe4 (N0.6C0.4) or Fe7 (N0.75C0.25)3 up to 60 GPa at room temperature. At high temperature, Fe7 (N0.75C0.25)3 transforms into the Fe3C-type phase at ∼27 GPa, and then into the Fe7C3-type phase at ∼45 GPa, which is also corroborated by our theoretical calculations. We found that the phase stability of iron carbonitrides mainly depends on the N/C ratio, and the elastic properties of iron carbonitrides are dominantly affected by the Fe/(N+C) ratio. Iron carbonitrides with diverse structures may be the main host for nitrogen in the deep mantle. Some iron carbonitride inclusions in lower mantle diamonds could be the residue of the primordial mantle or originate from subducted nitrogen-bearing materials, rather than iron-enriched phases of the outer core. In addition, our experiments confirmed the existence of Fe7C3-type Fe7C3-Fe7N3 solid solutions above 40 GPa. Fe7C3-type Fe7(C, N)3 has comparable density and thermoelastic properties to its isostructural endmembers and may be a promising candidate constituent of the Earth's inner core. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Deep nitrogen host; equation of state; inner core; iron carbonitride; phase transition; superdeep diamond
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/187088
作者单位	Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, Peking University and School of Earth and Space Sciences, Peking University, Beijing, China; Hawaiʻi Institute of Geophysics and Planetology, University of Hawaiʻi at Mānoa, Honolulu, HI, United States; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, China; Gemmological Institute, China University of Geosciences, Wuhan, China; Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, United States; Center for Advanced Radiation Sources, University of Chicago, Chicago, IL, United States
推荐引用方式 GB/T 7714	Huang S.,Wu X.,Zhu F.,et al. High-Pressure Phase Stability and Thermoelastic Properties of Iron Carbonitrides and Nitrogen in the Deep Earth[J],2021,126(6).
APA	Huang S..,Wu X..,Zhu F..,Lai X..,Li J..,...&Chen B..(2021).High-Pressure Phase Stability and Thermoelastic Properties of Iron Carbonitrides and Nitrogen in the Deep Earth.Journal of Geophysical Research: Solid Earth,126(6).
MLA	Huang S.,et al."High-Pressure Phase Stability and Thermoelastic Properties of Iron Carbonitrides and Nitrogen in the Deep Earth".Journal of Geophysical Research: Solid Earth 126.6(2021).