透射电镜质厚衬度成像和衍射衬度成像及相互转换的实验技术方法

摘要

Because transmission electron microscope (T EM ) can be used to show the details of micro-structure of various materials directly ,T EM has become one of the most important instruments for materi-al ultrafine structure study .Amplitude contrast is important for TEM images ,due to the information shown in TEM images resulting from such contrast .Usually ,amplitude contrast divide into mass-thick-ness contrast and diffraction contrast ,although mass-thickness contrast and diffraction contrast are based on the amplitude of electron wave ,because of the difference between their mechanisms ,the information in TEM images based on these two contrasts are different .In this article ,the techniques of imaging with mass-thickness contrast and diffraction contrast respectively are described in details .More information a-bout the microstructures in the same position can be revealed by combining the TEM images with different contrasts .%透射电子显微镜作为观察材料微结构的主要手段之一，其显微图像可直观揭示材料微结构信息和空间分布情况。振幅衬度是一种重要的显微成像衬度机制，基于振幅衬度能够使显微像揭示材料的微结构特征。尽管显微像衬度的产生都来源于电子波的振幅，但是振幅衬度像还可以进一步化分为质厚衬度像和衍射衬度像。由于像衬度形成机理的差异，质厚衬度像和衍射衬度像中所显示的微结构细节有明显不同。本文介绍了如何在透射电镜观察中实现质厚衬度成像和衍射衬度成像，及其相互转换的实验方法和操作技术细节。利用透射电镜的不同成像衬度模式能够在样品的同一视场中观察到更多的材料结构细节，可以在多层次和不同尺度上获得更丰富的微结构信息。