Developing image‐contrast theory and analysis methods in high‐resolution electron microscopy
Developing image‐contrast theory and analysis methods in high‐resolution electron microscopy
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DOI：
10.1002/pssa.201026459
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发表时间：
2010-12
期刊：
影响因子：
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通讯作者：
F. H. Li
中科院分区：
文献类型：
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作者：
F. H. Li
据认为，利用一组基于图像对比度理论开发的分析方法可以大大改善从高分辨率电子显微镜图像中获得的结构信息，该图像对比度理论专门用于显示图像强度随样品厚度的变化。介绍了通过反卷积处理将不代表被测样品结构的实验图像转化为结构图，结构分辨率提高到显微镜的信息极限，或者对于完美晶体，通过随后结合校正的电子衍射数据并利用X射线晶体学中发展的结构分析方法，将结构分辨率提高到电子衍射极限，并通过分析图像对比度随样品厚度的变化等，可以识别不同原子量的原子。图像对比度理论，演示了所开发的图像分析方法的原理和功能。给出了从头算晶体结构测定和原子水平晶体缺陷研究的典型应用示例。
It is reviewed that the structural information obtained from high‐resolution electron microscope images can be greatly improved by utilizing a group of analysis methods developed based on an image‐contrast theory derived particularly to show the image‐intensity change with the sample thickness. It is introduced that the experimental images that do not represent the structures of examined samples can be transformed into the structure maps by deconvolution processing with the structure resolution enhanced up to the information limit of the microscope, or further, for perfect crystals, to the electron diffraction limit by subsequently combining the corrected electron‐diffraction data and utilizing the structure analysis methods developed in X‐ray crystallography, and it becomes possible to recognize atoms with different atomic weights by analyzing the image‐contrast change with the sample thickness, etc. The derivation of the image‐contrast theory, the principle and functions of the developed image‐analysis methods are demonstrated. Typical examples of applications to the ab initio crystal‐structure determination and studies of crystal defects at atomic level are given.