Institut für Festkörperphysik, Universität Bremen, Bremen, 28359, Germany.
Institut für Festkörperphysik, Universität Bremen, Bremen, 28359, Germany.
Ultramicroscopy. 2018 Jul;190:45-57. doi: 10.1016/j.ultramic.2018.03.013. Epub 2018 Apr 12.
Strain analyses from experimental series of nano-beam electron diffraction (NBED) patterns in scanning transmission electron microscopy are performed for different specimen tilts. Simulations of NBED series are presented for which strain analysis gives results that are in accordance with experiment. This consequently allows to study the relation between measured strain and actual underlying strain. A two-tilt method which can be seen as lowest-order electron beam precession is suggested and experimentally implemented. Strain determination from NBED series with increasing beam convergence is performed in combination with the experimental realization of a probe-forming aperture with a cross inside. It is shown that using standard evaluation techniques, the influence of beam convergence on spatial resolution is lower than the influence of sharp rings around the diffraction disc which occur at interfaces and which are caused by the tails of the intensity distribution of the electron probe.
对扫描透射电子显微镜中的纳米束电子衍射 (NBED) 花样的实验系列进行应变分析，针对不同的试样倾斜角度。为 NBED 系列呈现了模拟结果，应变分析的结果与实验相符。这使得研究测量应变与实际基础应变之间的关系成为可能。建议并实验实现了一种双倾斜方法，可视为最低阶电子束进动。在与实验实现的具有内部十字的探头形成孔径相结合的情况下，从具有增加束收敛的 NBED 系列中进行应变确定。结果表明，使用标准评估技术，束收敛对空间分辨率的影响小于在界面处出现的衍射盘周围的锐环的影响，这些锐环是由电子探针强度分布的尾部引起的。
