Iga Haruka, Shimizu Toshiki, Minoda Hiroki
Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo 184-8588, Japan.
Microscopy (Oxf). 2024 Oct 4;73(5):414-421. doi: 10.1093/jmicro/dfae015.
We report a novel class of scanning transmission electron microscopy with Hilbert-differential phase contrast (HDP-STEM) that displays nanostructures of thin samples in a topographical manner. A semicircular π-phase plate (PP) was used as an optical device for manipulating electron waves in HDP-STEM. This is the different design from the Zernike PP used in our previous phase plate STEM (P-STEM), but both must be placed in the front focal plane of the condenser lens. HDP-STEM images of multiwalled carbon nanotubes showed higher contrast than those obtained by conventional bright-field STEM. As the PP of the HDP-STEM is nonsymmetrical, several different images were obtained by changing the detection conditions. A two-dimensional electron detector was also used to remove the scattering contrast component in the same way as with the Zernike PP and obtain an image containing only (differential) phase contrast.
我们报道了一种新型的具有希尔伯特微分相衬的扫描透射电子显微镜（HDP-STEM），它能以形貌方式显示薄样品的纳米结构。在HDP-STEM中，一个半圆形的π相板（PP）被用作操纵电子波的光学器件。这与我们之前的相板STEM（P-STEM）中使用的泽尼克相板设计不同，但两者都必须放置在聚光镜的前焦平面上。多壁碳纳米管的HDP-STEM图像显示出比传统明场STEM获得的图像更高的对比度。由于HDP-STEM的相板不对称，通过改变检测条件获得了几个不同的图像。还使用了二维电子探测器，以与泽尼克相板相同的方式去除散射对比度分量，并获得仅包含（微分）相衬的图像。
