Cylindrically symmetric rotating crystals observed in crystallization process of InSiO film

The Kikuchi bands arise from Bragg diffraction of incoherent electrons scattered within a crystalline specimen and can be observed in both the transmission and reflection modes of scanning electron microscopy (SEM). Converging, rocking, or grazing incidence beams must be used to generate divergent electron sources to obtain the Kikuchi pattern. This paper report the observation of Kikuchi pattern from SEM images of an exceptional rotating crystal with continuous rotation in the local crystal direction and satisfying cylindrical symmetry, named a cylindrically symmetric rotating crystal. By retracing the Kikuchi line pattern, it is possible to obtain the lattice structure information of the presented sample from the conventional SEM images. SEM images of cylindrically symmetric rotating crystals reflect the interactions between electrons and the sample in both the real- and momentum-space. It is a very interesting and representative new case for the study of the contrast mechanism in SEM. Unveiling a unique rotating crystal, the study expands the understanding of scanning electron microscopy (SEM) contrast mechanisms by simultaneously capturing real-space morphology and momentum-space lattice information in a single image.

菊池带（Kikuchi bands）源于晶体试样内部散射的非相干电子的布拉格衍射，可在扫描电子显微镜（SEM）的透射与反射模式下观测到。为获取菊池花样，需使用会聚、摇摆或掠入射电子束以产生发散电子源。本文报道了对一类特殊旋转晶体的SEM图像中菊池花样的观测结果：该晶体的局部晶体取向持续旋转且满足圆柱对称性，故被命名为圆柱对称旋转晶体。通过还原菊池线花样，可从常规SEM图像中提取所表征样品的晶格结构信息。圆柱对称旋转晶体的SEM图像可反映电子在实空间与动量空间中与样品的相互作用，是研究SEM衬度机制的极具趣味性与代表性的新型案例。本研究揭示了一种独特的旋转晶体，通过单张图像同时捕获实空间形貌与动量空间晶格信息，拓展了人们对扫描电子显微镜（SEM）衬度机制的认知。