中文摘要：

用200kV六硼化镧光源的高分辨透射电子显微镜观察了AlSb/GaAs（001）外延薄膜的失配位错,结合解卷处理方法把[110]高分辨电子显微像转换为试样的结构投影图,其分辨率接近电子显微镜的信息极限.根据赝弱相位物体近似像衬理论,通过分析AlSb薄膜完整区解卷像的衬度随试样厚度的变化,确定了哑铃原子对中Al和Sb原子的位置.在此基础上构建出失配位错的结构模型,再结合模拟像与实验像的匹配,确定了AlAs型界面以及Lomer和60°两类失配全位错的核心结构.

英文摘要：

The detailed core structures of misfit dislocations in the AlSb/GaAs（001） hetero structure system were studied by 200 kV LaB_6 filament high-resolution electron microscope. In combination with image deconvolution, the [110] images were transformed into the projected structure maps, and the image resolution was enhan ced up to the information limit of the microscope. To distinguish Al and Sb atoms in the AlSb film, the image contrast change with the sample thickness was analyzed for the perfect region in deconvoluted image, and the positions of Al and Sb atoms in the dumbbells were determined based on the image contrast theory of the pseudo-weak-phase object approximation. Then the structure models of two types of misfit dislocations were constructed. As the simulated images are in good agreement with the experimental images, the AlAs type interface and the core structures of obtained Lomer and 60° misfit dislocations were determined.