Structure and Density of Fe-C Liquid Alloys Under High Pressure
Structure and Density of Fe-C Liquid Alloys Under High Pressure
复制标题
高压下铁碳液态合金的结构和密度
DOI：
10.1002/2017jb014779
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发表时间：
2017
期刊：
影响因子：
3.4
通讯作者：
Morard G
中科院分区：
文献类型：
--
作者：
Morard G
利用巴黎-爱丁堡压机和激光加热的金刚石砧细胞，用原位X射线衍射测量了液态Fe - C合金的密度和结构，温度高达58 GPa和3200 K。研究由X射线衍射测量推断的局部结构的压力演化对理解液体的压缩机制具有重要意义。得到的数据表明，第一配位球的压缩程度大于第二和第三配位球。测量密度的外推表明，碳不可能是地球核心中唯一与铁合金的轻元素，因为在% C （1.8-3.7 wt % C）下，8-16是解释相对于纯铁的外核密度缺陷所必需的。这种浓度太高，无法解释外核的速度。因此需要其他轻元素（如O、Si、S和H）的存在。
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.