Accurate structure determination from image reconstruction in ADF STEM

Conference item

Annular dark-field (ADF) imaging in a scanning transmission electron microscope results in direct structure images of the atomic configuration of the specimen. Since such images are almost perfectly incoherent they can be treated as a convolution between a point-spread function, which is simply the intensity of the illuminating electron probe, and a sharply peaked object function that represents the projected structure of the specimen. Knowledge of the object function for an image region of perfect crystal allows the point-spread function to be directly determined for that image. We examine how the object function for an image can then be reconstructed using a Wiener filter, the CLEAN algorithm and a maximum entropy reconstruction, Prior information is required to perform a reconstruction, and we discuss what nature of prior information is suitable for ADF imaging.

Authors: Nellist, P; Pennycook, S

• Publication status: Published
• Journal: JOURNAL OF MICROSCOPY-OXFORD
• Volume: 190
• Issue: 1-2
• Pages: 159-170
• Publication date: 1998-01-01
• Event title: International Workshop on Image Analysis Methods in Quantitative TEM
• DOI: 10.1046/j.1365-2818.1998.3260881.x
• EISSN: 1365-2818
• ISSN: 0022-2720
• Keywords: STEM; image reconstruction; probe reconstruction; ADF; structure determination; incoherent imaging