An automated acquisition system for collecting a large number of electron holograms, to improve the statistical precision of phase analysis, was developed. A technique for shifting the electron beam in combination with stage movement allows data to be acquired over a wide area of a TEM-specimen grid. Undesired drift in the hologram position, which may occur during the hologram acquisition, can be corrected in real time by automated detection of the interference-fringe region in an image. To demonstrate the usefulness of the developed automated hologram acquisition system, gold nanoparticles dispersed on a carbon foil were observed with a 1.2-MV atomic resolution holography electron microscope. The system could obtain 1024 holograms, which provided phase maps for more than 500 nanoparticles with a lateral resolution of 0.14 nm, in just 1 h. The observation results revealed an anomalous increase in mean inner potential for a particle size smaller than 4 nm. The developed automated hologram acquisition system can be applied to improve the precision of phase measurement by averaging many phase images, as demonstrated by single particle analysis for biological entities. Moreover, the system makes it possible to study electrostatic potential of catalysts and other functional nanoparticles at atomic resolution.

中文翻译：

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自动获取大量具有原子级相位信息的电子全息图

开发了一种用于收集大量电子全息图的自动采集系统，以提高相位分析的统计精度。将电子束与载物台移动相结合的技术允许在 TEM 样品网格的大范围内采集数据。在全息图采集期间可能发生的全息图位置的不希望的漂移可以通过自动检测图像中的干涉条纹区域来实时校正。为了证明开发的自动全息图采集系统的实用性，使用 1.2-MV 原子分辨率全息电子显微镜观察了分散在碳箔上的金纳米粒子。该系统可以在短短 1 小时内获得 1024 张全息图，提供 500 多个纳米粒子的相位图，横向分辨率为 0.14 nm。观察结果显示，对于小于 4 nm 的粒径，平均内部电位异常增加。开发的自动全息图采集系统可用于通过对许多相位图像进行平均来提高相位测量的精度，如生物实体的单粒子分析所示。此外，该系统可以在原子分辨率下研究催化剂和其他功能性纳米粒子的静电势。