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Abstract：
Micropillar compression is a method of choice to understand mechanics at small scale. It is mainly studied with electron microscopy or white-beam micro-Laue X-ray diffraction. The aim of the present article is to show the possibilities of the use of diffraction with a coherent X-ray beam. InSb micropillars in epitaxy with their pedestals (i.e. their support) are studied in situ during compression. Firstly, an experiment using a collimated beam matching the pillar size allows determination of when the sample enters the plastic regime, independently of small defects induced by experimental artefacts. A second experiment deals with scanning X-ray diffraction maps with a nano-focused beam; despite the coherence of the beam, the contributions from the pedestal and from the micropillar in the diffraction patterns can be separated, making possible a spatially resolved study of the plastic strain fields. A quantitative measurement of the elastic strain field is nevertheless hampered by the fact that the pillar diffracts at the same angles as the pedestal. Finally, no image reconstructions were possible in these experiments, either in situ due to a blurring of the fringes during loading or post-mortem because the defect density after yielding was too high. However, it is shown how to determine the elastic bending of the pillar in the elastic regime. Bending angles of around 0.3° are found, and a method to estimate the sample\'s radius of curvature is suggested.
摘要：
微柱压缩是理解小规模力学的一种选择方法。主要用电子显微镜或白光束显微X射线衍射进行研究。本文的目的是显示使用相干X射线束的衍射的可能性。在压缩过程中原位研究了具有其基座（即其支撑体）的外延中的InSb微柱。首先,使用与柱尺寸匹配的准直光束的实验可以确定样品何时进入塑性状态，独立于实验伪影引起的小缺陷。第二个实验涉及使用纳米聚焦光束扫描X射线衍射图；尽管光束具有相干性，衍射图案中来自基座和微柱的贡献可以分开，使塑性应变场的空间分辨研究成为可能。然而,由于柱以与基座相同的角度衍射的事实,阻碍了弹性应变场的定量测量。最后,在这些实验中不可能重建图像，无论是在原位由于模糊的条纹在加载或事后，因为缺陷密度后屈服太高。然而,显示了如何确定弹性状态下支柱的弹性弯曲。弯曲角度约为0.3°，并提出了一种估计样本曲率半径的方法。
