Based on column approximation (CA) assumption, many‐beam Schaeublin–Stadelmann diffraction equations are employed for simulating the transmission electron microscopy (TEM) diffraction image contrast of dislocation loops within thin TEM foil of finite thickness, and two beam and many beam diffraction conditions are compared. Moreover, the effects of materials anisotropy and free surface relaxation induced elastic fields distortion of dislocation loops on the black‐white image contrast are specially focused. It is found that anisotropy has a remarkable impact on the TEM image contrast of dislocation loop, and free surface relaxation induced image forces can change the black‐white contrast features when dislocation loops are near TEM foil free surfaces. Thus, in order to make reliable judgment on the nature of defects, effects of free surface and anisotropy should be included when analysing irradiation induced dislocation loops and other type of defects in in‐situ electron, proton, heavy‐ion irradiation experiments under TEM environments.

中文翻译：

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各向异性和像力对位错环 TEM 衍射对比度的协同作用

基于柱近似 (CA) 假设，采用多光束 Schaeublin-Stadelmann 衍射方程模拟有限厚度薄 TEM 箔内位错环的透射电子显微镜 (TEM) 衍射图像对比度，以及两光束和多光束衍射条件被比较。此外，特别关注了材料各向异性和自由表面松弛引起的位错环弹性场畸变对黑白图像对比度的影响。发现各向异性对位错环的 TEM 图像对比度有显着影响，当位错环靠近 TEM 箔自由表面时，自由表面弛豫诱导的图像力可以改变黑白对比度特征。因此，为了对缺陷的性质做出可靠的判断，