论文标题
互补的ADF-STEM：一种灵活的定量4D-STEM的方法
Complementary ADF-STEM: a Flexible Approach to Quantitative 4D-STEM
论文作者
论文摘要
扫描透射电子显微镜（STEM）在材料表征方面具有广泛的应用，包括实际空间成像，光谱和衍射，从微米到子 - Ångström的长度尺度。高速，直接电子茎检测器的最新开发和采用使每个探针位置都可以收集衍射模式，从而生成四维词干（4D-STEM）数据集并打开新的成像方式。但是，这些检测器中有限的像素数量在角度分辨率和最大收集角度之间实现了权衡。在本文中，我们通过利用电子束的完整通量来描述一种简单的方法，用于量化4D茎数据，包括散布在检测器极限之外的电子。这可以显着提高实验灵活性，包括从低角度衍射模式的定量，高对比度互补环形暗场（CADF）茎图像合成，同时保持高角度分辨率；以及电子剂量的优化和低动态范围检测器的更有效使用。
Scanning transmission electron microscopy (STEM) has a broad range of applications in materials characterization, including real-space imaging, spectroscopy, and diffraction, at length scales from the micron to sub-Ångström. The recent development and adoption of high-speed, direct electron STEM detectors has enabled diffraction patterns to be collected at each probe position, generating four-dimensional STEM (4D-STEM) datasets and opening new imaging modalities. However, the limited pixel numbers in these detectors enforce a tradeoff between angular resolution and maximum collection angle. In this paper, we describe a straightforward method for quantifying 4D-STEM data by utilizing the full flux of the electron beam, including electrons scattered beyond the limits of the detector. This enables significantly increased experimental flexibility, including the synthesis of quantitative, high-contrast complementary annular dark field (cADF) STEM images from low-angle diffraction patterns whilst maintaining high angular resolution; as well as the optimization of electron dose and the more effective use of low dynamic range detectors.
