Howe J M, Rozeveld S J
Department of Materials Science and Engineering, University of Virginia, Charlottesville 22903.
Microsc Res Tech. 1992 Nov 1;23(3):230-8. doi: 10.1002/jemt.1070230306.
The effects of crystal and beam tilt on high-resolution transmission electron microscope (HRTEM) images of planar coherent interfaces were investigated by multislice image simulations. It was found that a beam tilt of 0.5 Bragg angle (theta B) was sufficient to introduce detrimental artifacts into most images of interfaces in crystals only 1/8 xi 000 thick, while crystal tilt had a much smaller effect even for crystals 1 xi 000 thick. Effects produced in HRTEM images of interfaces by crystal and beam tilt included the introduction of additional periodicities and loss of compositional detail across a boundary, translation of a boundary from its actual position, and apparent mismatch of atomic planes across a perfectly coherent interface. These results indicate that alignment of the electron beam parallel to the optic axis is critical for reliable HRTEM imaging of interfaces in materials. Techniques for obtaining accurate alignment are also discussed.
通过多层图像模拟研究了晶体倾斜和电子束倾斜对平面相干界面的高分辨率透射电子显微镜（HRTEM）图像的影响。研究发现，仅1/8ξ000厚的晶体中，0.5布拉格角（θB）的电子束倾斜就足以在大多数界面图像中引入有害伪像，而即使对于1ξ000厚的晶体，晶体倾斜的影响也要小得多。晶体倾斜和电子束倾斜在界面的HRTEM图像中产生的影响包括引入额外的周期性、边界处成分细节的丢失、边界从其实际位置的平移以及完全相干界面处原子平面的明显失配。这些结果表明，电子束与光轴平行的对准对于材料界面的可靠HRTEM成像至关重要。还讨论了获得精确对准的技术。
