Premium
Structure and Density of Fe‐C Liquid Alloys Under High Pressure
Author(s) -
Morard G.,
Nakajima Y.,
Andrault D.,
Antonangeli D.,
Auzende A. L.,
Boulard E.,
Cervera S.,
Clark A. N.,
Lord O. T.,
Siebert J.,
Svitlyk V.,
Garbarino G.,
Mezouar M.
Publication year - 2017
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2017jb014779
Subject(s) - diffraction , diamond anvil cell , extrapolation , core (optical fiber) , materials science , compression (physics) , crystallography , spheres , powder diffraction , diamond , relative density , outer core , coordination number , analytical chemistry (journal) , chemistry , optics , metallurgy , ion , composite material , physics , microstructure , mathematical analysis , mathematics , chromatography , astronomy , organic chemistry
The density and structure of liquid Fe‐C alloys have been measured up to 58 GPa and 3,200 K by in situ X‐ray diffraction using a Paris‐Edinburgh press and laser‐heated diamond anvil cell. Study of the pressure evolution of the local structure inferred by X‐ray diffraction measurements is important to understand the compression mechanism of the liquid. Obtained data show that the degree of compression is greater for the first coordination sphere than the second and third coordination spheres. The extrapolation of the measured density suggests that carbon cannot be the only light element alloyed to iron in the Earth's core, as 8–16 at % C (1.8–3.7 wt % C) would be necessary to explain the density deficit of the outer core relative to pure Fe. This concentration is too high to account for outer core velocity. The presence of other light elements (e.g., O, Si, S, and H) is thus required.