DOI: 10.1002/2016GL071353
论文题名: Phase relations of Fe3C and Fe7C3 up to 185 GPa and 5200 K: Implication for the stability of iron carbide in the Earth's core
作者: Liu J. ; Lin J.-F. ; Prakapenka V.B. ; Prescher C. ; Yoshino T.
刊名: Geophysical Research Letters
ISSN: 0094-8296
EISSN: 1944-8027
出版年: 2016
卷: 43, 期: 24 起始页码: 12415
结束页码: 12422
语种: 英语
英文关键词: Earth's core
; iron carbide
; melting
; X-ray diffraction
Scopus关键词: Carbides
; Iron
; Melting
; Bulk compositions
; Diffuse scattering
; Earth's core
; Higher melting points
; Iron carbides
; Laser-heated diamond cells
; Melting behavior
; Relative stabilities
; X ray diffraction
英文摘要: We have investigated phase relations and melting behavior of Fe3C and Fe7C3 using X-ray diffraction in a laser-heated diamond cell up to 185 GPa and 5200 K. Our results show that the starting Fe3C sample decomposes into a mixture of solid orthorhombic Fe7C3 and hcp-Fe at above 145 GPa upon laser heating and then transforms into Fe-C liquid and solid Fe7C3 at temperatures above 3400 K. Using the intensity of the diffuse scattering as a primary criteria for detecting melting, the experimentally derived liquidus for a bulk composition of Fe3C fitted with the Simon-Glatzel equation is Tm(K) = 1800 × [1 + (Pm − 5.7)/15.10 ± 2.55]1/2.41 ± 0.17 at 24–185 GPa, which is ~500 K higher than the melting curve of iron reported by Anzellini et al. (2013) at Earth's core pressures. The higher melting point and relative stability of Fe7C3 in Fe-rich Fe-C system at Earth's core conditions indicate that Fe7C3 could solidify out of the early Earth's molten core to become a constituent of the innermost inner core. ©2016. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007504679&doi=10.1002%2f2016GL071353&partnerID=40&md5=49210b969292e8ccad7c44c423b601e0
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/9259
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States
Recommended Citation:
Liu J.,Lin J.-F.,Prakapenka V.B.,et al. Phase relations of Fe3C and Fe7C3 up to 185 GPa and 5200 K: Implication for the stability of iron carbide in the Earth's core[J]. Geophysical Research Letters,2016-01-01,43(24).