Development and Applications of Pixelated STEM Detector

Ryusuke Sagawa, Kazunori Somehara, Tomohisa Fukuda, Takamitsu Saito, Hiroki Hashiguchi, Hirokazu Sasaki and Yukihito Kondo

Abstract: In scanning transmission electron microscopy (STEM), one can obtain a variety of STEM images such as bright-field (BF), annular dark-field (ADF) and differential phase contrast (DPC) images with variously shaped detectors. However, the information in a diffraction patterns on the detector plane is not fully utilized, when we use conventional detectors, as they integrate the intensity over the scintillator. Meanwhile, direct electron detectors whose frame rate and number of pixels are thousands fps and more than several ten thousand pixels, have recently been commercialized and used in STEM. Such detectors, when used for recording the diffraction patterns for STEM probe positions, are called pixelated STEM detectors. With the obtained 4-dimensional dataset, a variety of STEM images can be synthesized in a post or real time processing. We have developed a fast pixelated STEM detector and integrated it into our electron microscopes. Here, we report the hardware and its application data taken with the detector.

Key words: pixelated STEM detector, ptychography, electric field map, magnetic field map, phase image