电子晶体学图像处理及其在材料科学中的应用

Electron Crystallography Image Processing and Its Applications in Materials Science

摘要:

本文指出，借助高分辨电子显微镜观察到的显微像并不总直观地反映晶 体结构，对于在特定离焦条件下拍摄到的结构像，其分辨率还要受显微镜分辨本领的限制，只有超高压高分辨电子显微镜才能直接给出原子分辨率的结构像。文章介绍了衍射晶体学与高分辨电子显微学相结合起来的优越性，和据此发展的电子晶体学图像处理技术，用此技术可以实现“从头”测定晶体结构，并能把中等电压电子显微镜得到的结构像分辨率约提高1倍，达到原子分辨率。文中举例介绍了此技术在测定晶体结构和缺陷中的应用。

Abstract:

It is pointed out that the images obtained by high-resolution electron microscopes is not always reflect the crystal structure directly, and the resolution of the structure image taken under a certain defocus condition is limited by the resolution of the electron microscope. The structure image with atomic resolution can be directly obtained only with the high-voltage high-resolution electron microscopes. The advantage of introducing diffraction analysis into high-resolution electron microscopy (HREM) is clarified,and an electron crystallographic image processing technique set up by combining the diffraction crystallography with HREM is introduced in the present paper. This technique makes realizable the ab initio crystal structure determination by HREM. It is shown that the resolution of the structure image obtained with a medium-voltage electron microscope can be enhanced up to the atomic resolution.Examples of applying this technique to the study of crystal structures and defects are given.