Microscopic structural change in a liquid Fe-C alloy of ~5 GPa
Microscopic structural change in a liquid Fe-C alloy of ~5 GPa
复制标题
~5 GPa 液态 Fe-C 合金的微观结构变化
DOI：
10.1002/2015gl064271
复制
发表时间：
2015
影响因子：
5.2
通讯作者：
Yingwei Fei
中科院分区：
文献类型：
--
作者：
Yuki Shibazaki;Yoshio Kono;Yingwei Fei
使用巴黎-爱丁堡型大体积压力机，通过多角度能量色散X射线衍射，在高达7.2 GPa的压力下检查液态Fe-3.5 wt % C合金的结构。X射线衍射数据显示，在5 GPa下，结构因子和约化对分布函数的压力依赖性峰位发生了明显变化。这些结果表明，液态Fe-3.5重量% C合金在约5 GPa下发生结构变化。这一发现为之前在相同压力下观察到的合金密度变化提供了微观解释。液态Fe-3.5 wt % C合金的最近邻距离和第二邻距离的压力依赖性与液态Fe相似，液态Fe在bcc-fcc-液态三相点（5.2 GPa和1991 K）附近表现出结构变化。Fe-3.5 wt % C和Fe之间的相似性表明，密度变化也发生在液态Fe中，并且这种结构变化延伸到其他Fe-轻元素合金。
The structure of a liquid Fe‐3.5 wt % C alloy is examined for up to 7.2 GPa via multiangle energy‐dispersive X‐ray diffraction using a Paris‐Edinburgh type large‐volume press. X‐ray diffraction data show clear changes in the pressure‐dependent peak positions of structure factor and reduced pair distribution function at 5 GPa. These results suggest that the liquid Fe‐3.5 wt % C alloys change structurally at approximately 5 GPa. This finding serves as a microscopic explanation for the alloy's previously observed density change at the same pressure. The pressure dependencies of the nearest and second neighbor distances of the liquid Fe‐3.5 wt % C alloy are similar to those of liquid Fe which exhibits a structural change near thebcc‐fcc‐liquid triple point (5.2 GPa and 1991 K). Similarities between Fe‐3.5 wt % C and Fe suggest that a density change also occurs in liquid Fe and that this structural change extends to other Fe‐light element alloys.