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 multi-walled carbon nanotubes showed higher contrast than those obtained by conventional bright-field STEM. Since 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.

中文翻译：

---

希尔伯特微分相衬在扫描透射电子显微镜中的应用

我们报告了一种新型的希尔伯特微分相衬扫描透射电子显微镜（HDP-STEM），它以形貌方式显示薄样品的纳米结构。半圆形π相位板（PP）被用作HDP-STEM中操纵电子波的光学装置。这与我们之前的相位板 STEM (P-STEM) 中使用的 Zernike PP 的设计不同，但两者都必须放置在聚光镜的前焦平面中。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PP是不对称的，因此通过改变检测条件可以获得多个不同的图像。还使用二维电子探测器以与 Zernike PP 相同的方式去除散射对比度分量，并获得仅包含（微分）相位对比度的图像。