Maccagnano-Zacher S E, Mkhoyan K A, Kirkland E J, Silcox J
School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA.
Ultramicroscopy. 2008 Jul;108(8):718-26. doi: 10.1016/j.ultramic.2007.11.003. Epub 2007 Nov 13.
A study of the effects of small-angle specimen tilt on high-resolution annular dark field images was carried out for scanning transmission electron microscopes with uncorrected and aberration-corrected probes using multislice simulations. The results indicate that even in the cases of specimen tilts of the order of 1 degree a factor of 2 reduction in the contrast of the high-resolution image should be expected. The effect holds for different orientations of the crystal. Calculations also indicate that as the tilted specimen gets thicker the contrast reduction increases. Images simulated with a low-angle annular dark field detector show that tilt effects are more pronounced in this case and suggest that these low-angle detectors can be used to correct specimen tilt during scanning transmission electron microscopes operation.
利用多切片模拟，对未校正和像差校正探针的扫描透射电子显微镜进行了小角度样品倾斜对高分辨率环形暗场图像影响的研究。结果表明，即使在样品倾斜约1度的情况下，高分辨率图像的对比度也会降低2倍。这种效应适用于晶体的不同取向。计算还表明，随着倾斜样品变厚，对比度降低会增加。用低角度环形暗场探测器模拟的图像表明，在这种情况下倾斜效应更明显，并表明这些低角度探测器可用于在扫描透射电子显微镜操作期间校正样品倾斜。
