2019 年 127 巻 10 号 p. 708-714
Ultra-high spatial resolution better than 0.5 Å has been achieved in aberration-corrected scanning transmission electron microscopy (STEM). By combining such an ultra-high resolution STEM with a differential phase contrast (DPC) imaging technique, we can now directly visualize the electric field distribution inside individual atoms in real space. The atomic electric field, i.e., the field between the nucleus of the atom and the electron cloud that surrounds it, contains information about the atomic species and charge redistribution due to chemical bonding. In this review, the current status of the development in atomic-resolution DPC STEM and its future direction is discussed.