Presentation Information
[R1P-02]Toward the development of 4D-STEM (electron diffraction Imaging) in mineralogy
*Akira MIYAKE1, Yohei Igami1 (1. Kyoto University)
Keywords:
electron microscopy,electron diffraction imaging,4D-STEM
The four-dimensional scanning transmission electron microscopy (4D-STEM) method (electron diffraction imaging), in which a focused electron probe in scanning transmission electron microscopy (STEM) is scanned in a two-dimensional (2D) manner while synchronously using a two-dimensional detector to record the electron diffraction pattern (2D diffraction pattern) at each probe position to acquire four-dimensional (4D) array data, has attracted attention and is widely used [1]. This enables the acquisition of data such as lattice constants, orientation and phase maps, as well as strain analysis, suggesting that the technique will be widely adopted in the fields of mineralogy and earth and planetary sciences. At the 2025 Annual Meeting of the Mineralogical Society of Japan, Igami and Miyake presented a system constructed using a TEM (JEOL, JEM-2100F) installed at Kyoto University. Using script control (Gatan, Digital Micrograph), synchronization between electron beam nanoprobe scanning (Gatan, DigiScan II) and diffraction pattern acquisition with a CCD camera (Gatan, Orius200D) was achieved, enabling the acquisition and analysis of 4D diffraction imaging array data from the mineral samples. In this system, we prepared a simple GUI with an original script and implemented a beam scan calibration function to enable distortion-suppressed beam scanning over various beam conditions and scan ranges. However, this system has issues, such as requiring several minutes to several tens of minutes to acquire data because of the use of a CCD camera and script-controlled electron probe scanning. Moreover, for future developments, such as high-temperature in situ observations or indentation in situ observations, we considered that data acquisition at speeds 1–2 orders of magnitude faster than script control would be necessary. Therefore, we introduced a new “hybrid” direct electron detector (Dectris, QUADRO) and a compatible scan generator (point electronic, REVOLON) to the existing TEM. As a result, 4D-STEM data were acquired at speeds more than an order of magnitude faster than those of conventional script-controlled 4D-STEM acquisition. In this presentation, we introduce the specific content and research examples of this newly introduced system. Additionally, the applications to mineralogy and earth and planetary sciences will be introduced in another presentations by Igami et al. and so on at this annual meeting.
Reference: [1] Ophus, C. (2019) Microsc. Microanal. 25, 563.
Reference: [1] Ophus, C. (2019) Microsc. Microanal. 25, 563.