Naoya Shibata1 2

1, The University of Tokyo, Tokyo, , Japan
2, Japan Fine Ceramics Center, Nagoya, , Japan

Due to the rapid progresses in segmented/pixelated detector developments combined with the state-of-the-art aberration correction technologies, atomic-resolution differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM) is now becoming feasible. It has been shown that atomic resolution DPC STEM can visualize atomic electric field, the field between positively charged atomic nucleus and negatively charged surrounding electron clouds [1-3]. In this study, we use high-speed segmented type detector combined with a center of mass detection method [4] to quantitatively image atomic electric field of atomic columns in crystalline materials and even inside individual single atoms. We show that the (projected) atomic electric field points outward from the center of the atomic columns very clearly, reflecting the presence of positive atomic nucleus and negative surrounding electrons. In this talk, current status and prospects for aberration-corrected DPC STEM with high-speed segmented detector will be discussed. This work was supported by SENTAN, JST, and the JSPS KAKENHI Grant number JP17H01316.

[1] N. Shibata et al., Nature Phys., 8, 611-615 (2012).
[2] K. Müller et al., Nature. Comm. 5, 5653 (2014).
[3] N. Shibata et al., Nature Comm. 8, 15631 (2017).
[4] R. Close et al., Ultramicroscopy 159, 124–137 (2015).