一种基于EBSD的晶体结构缺陷解析新方法

扫描电镜下的电子背散射衍射（EBSD）方法是一种能够快速高效定量统计研究材料晶体结构及取向，并能够将晶体结构及取向信息与微观形貌相对应的新方法，是当今材料科技工作者极其需要的一种分析技术。然而，当前EBSD方法在晶体结构分析方面还有很大的局限性：无法解析晶体结构缺陷。采用EBSD技术解析晶体结构缺陷遇到的瓶颈问题是：如何获得晶体缺陷结构EBSD参考花样? 如何获得高分辨率的晶体缺陷结构EBSD实验花样？本项目中，我们拟通过发展基于低能电子衍射动力学理论的晶体缺陷结构EBSD花样模拟方法，获得各种晶体缺陷结构参考花样，揭示结构缺陷与花样特征之间的关联，指导如何从实验花样中提炼晶体缺陷结构；通过采用透射式背散射电子衍射（t-EBSD）技术，获得高分辨率的晶体缺陷结构实验花样，提炼晶体缺陷结构模型；通过把用提炼结构模型模拟、精修的参考花样与实验花样进行比对，确定晶体结构缺陷。

Electron backscattered diffraction (EBSD) in scanning electron microscopy (SEM) is a viable method for efficiently and quantitatively determining the microscopic morphology, crystal structure, and orientation at the same time. This kind of analysis is highly needed for material science and technology. However, the current EBSD method has a great limitation in crystal structure analysis, which cannot be applied to analyze crystal defects. The bottleneck problems of using the EBSD method to analyze crystal defects are how to obtain reference EBSD patterns, and how to obtain high resolution experimental EBSD patterns. In this project, we intend to obtain various reference patterns of crystal defects by developing EBSD pattern simulation methods based on the dynamical low energy electron diffraction theory, to reveal the correlation between the defects and the pattern characteristics, and to guide the extraction of the crystal defect models from experimental patterns. By using transmission backscatter electron diffraction (t-EBSD) techniques, high resolution experimental patterns of the crystal defects will be obtained, and the crystal defect models will be extracted. The accurate structure of the crystal defects will be determined by comparing the reference patterns that are obtained from simulations and further refined using the extracted crystal defect models with the experimental patterns.