Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
Microscopy (Oxf). 2022 Apr 1;71(2):117-123. doi: 10.1093/jmicro/dfac004.
A two-dimensional (2D) detector was used to construct phase plate STEM (P-STEM) images. Phase-contrast can be enhanced by the electron intensity inside the hole region of a thin film phase plate. The electron intensity outside the hole region also provides a dark image contrast, which is inconsistent with the weak phase object approximation. We consider that both images have scattering effects that provide a dark contrast. Therefore, scattering contrast was derived by summing these two images, and scattering effects were subtracted from each image to display negative and positive phase contrast. The resultant images are consistent with the weak phase object approximation. These results propose separating scattering (electron amplitude) and phase-contrast (electron phase) using P-STEM, along with a two-dimensional electron detector.
使用二维（2D）探测器构建相衬扫描透射电子显微镜（P-STEM）图像。薄相位板的孔区中的电子强度可以增强相位对比。孔区外的电子强度也提供了暗场图像对比，这与弱相位物体近似不一致。我们认为这两个图像都具有散射效应，提供了暗对比度。因此，通过将这两个图像相加得到散射对比度，并从每个图像中减去散射效应，以显示负相和正相对比度。得到的图像与弱相位物体近似一致。这些结果提出了使用 P-STEM 和二维电子探测器分离散射（电子幅度）和相衬（电子相位）。
