Hofmann Felix, Phillips Nicholas W, Harder Ross J, Liu Wenjun, Clark Jesse N, Robinson Ian K, Abbey Brian
Department of Engineering Science, University of Oxford, Parks Road, Oxford OX2 7TL, United Kingdom.
Department of Chemistry and Physics, La Trobe University, Victoria 3086, Australia.
J Synchrotron Radiat. 2017 Sep 1;24(Pt 5):1048-1055. doi: 10.1107/S1600577517009183. Epub 2017 Aug 8.
Multi-reflection Bragg coherent diffraction imaging has the potential to allow three-dimensional (3D) resolved measurements of the full lattice strain tensor in specific micro-crystals. Until now such measurements were hampered by the need for laborious, time-intensive alignment procedures. Here a different approach is demonstrated, using micro-beam Laue X-ray diffraction to first determine the lattice orientation of the micro-crystal. This information is then used to rapidly align coherent diffraction measurements of three or more reflections from the crystal. Based on these, 3D strain and stress fields in the crystal are successfully determined. This approach is demonstrated on a focused ion beam milled micro-crystal from which six reflections could be measured. Since information from more than three independent reflections is available, the reliability of the phases retrieved from the coherent diffraction data can be assessed. Our results show that rapid, reliable 3D coherent diffraction measurements of the full lattice strain tensor in specific micro-crystals are now feasible and can be successfully carried out even in heavily distorted samples.
多反射布拉格相干衍射成像技术有潜力对特定微晶中的全晶格应变张量进行三维（3D）分辨测量。到目前为止，此类测量因需要繁琐、耗时的对准程序而受到阻碍。本文展示了一种不同的方法，利用微束劳厄X射线衍射首先确定微晶的晶格取向。然后利用该信息快速对准来自晶体的三个或更多反射的相干衍射测量。基于这些，成功确定了晶体中的3D应变和应力场。该方法在一个聚焦离子束研磨的微晶上得到了验证，从该微晶上可以测量到六个反射。由于有来自三个以上独立反射的信息，因此可以评估从相干衍射数据中检索到的相位的可靠性。我们的结果表明，现在对特定微晶中的全晶格应变张量进行快速、可靠的3D相干衍射测量是可行的，甚至在严重畸变的样品中也能成功进行。
