Determination of the strain field from an HREM image of a Si Lomer dislocation

摘要

A new approach to quantitative deformation characterization of high-resolution electron microscopy (HREM) defect images has been developed. The principle of this technique, (Computational Fourier Transform Deformation (CFTD)) is to extract an accurate displacement field about a defect from its HREM image using Fourier transformation procedures. The methodology's unique feature is to digitize the defect image and compute the Moire pattern, from which the displacement field is obtained, without the need for an external reference lattice image, normally associated with the interference phenomena. From this data, the displacement gradient can be calculated, which yields much information on the experimental deformation mechanics. One question that has arisen is whether different imaging conditions of the same defect affects the results of the CFM analysis. We have studied this problem by analyzing the strain components of simulated images of a Lomer dislocation in Si and present our findings here.