Study of partial melting at high-pressure using in situ X-ray diffraction
Study of partial melting at high-pressure using in situ X-ray diffraction
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利用原位 X 射线衍射研究高压部分熔化
DOI：
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发表时间：
2006
期刊：
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通讯作者：
M. Mezouar
中科院分区：
文献类型：
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作者：
D. Andrault;G. Morard;N. Bolfan;O. Ohtaka;H. Fukui;H. Arima;N. Guignot;K. Funakoshi;P. Lazor;M. Mezouar
使用经典的基于同步加速器的原位 X 射线衍射技术研究了不同铁合金的高压熔化行为。由于它们具有特定的优点和缺点，能量色散 (EDX) 和角度色散 (ADX) X 射线衍射方法分别在 SPring8（日本）的 BL04B1 光束线和 ESRF（法国）的 ID27-30 光束线上进行。研究的高压容器和压力范围包括 2 至 17 GPa 的巴黎-爱丁堡压力机、10 至 27 GPa 的 SPEED-1500 多砧压力机以及 15 至 60 GPa 的激光加热金刚石砧室。使用 EDX 可以轻松检测熔化的开始（在固相线或共晶温度），因为晶粒开始相对于 X 射线束旋转，这会随着峰值生长速率的时间而引起快速而剧烈的变化。然后，可以使用EDX和ADX两者，根据液相的漫射X射线散射特性的强度来确定熔化程度。这种扩散贡献可以很容易地与压力介质的康普顿扩散区分开来，因为它们在衍射图案中具有不同的形状。然后可以从漫X射线散射的形状中提取关于液相的组成和/或结构的信息。
The high-pressure melting behavior of different iron alloys was investigated using the classical synchrotron-based in situ X-ray diffraction techniques. As they offer specific advantages and disadvantages, both energy-dispersive (EDX) and angle-dispersive (ADX) X-ray diffraction methods were performed at the BL04B1 beamline of SPring8 (Japan) and at the ID27-30 beamline of the ESRF (France), respectively. High-pressure vessels and pressure ranges investigated include the Paris–Edinburgh press from 2 to 17 GPa, the SPEED-1500 multi-anvil press from 10 to 27 GPa, and the laser-heated diamond anvil cell from 15 to 60 GPa. The onset of melting (at the solidus or eutectic temperature) can be easily detected using EDX because the grains start to rotate relative to the X-ray beam, which provokes rapid and drastic changes with time of the peak growth rate. Then, the degree of melting can be determined, using both EDX and ADX, from the intensity of diffuse X-ray scattering characteristic of the liquid phase. This diffuse contribution can be easily differentiated from the Compton diffusion of the pressure medium because they have different shapes in the diffraction patterns. Information about the composition and/or about the structure of the liquid phase can then be extracted from the shape of the diffuse X-ray scattering.