1 JEOL Ltd.2 Kyushu UniversityFig 1 Phase images of Au particles taken at (a) infocus and (b) 100 nm defocused conditions reconstructed by ptychography.78Kazutaka Mitsuishi1 and Katsuaki Nakazawa21 Center for Basic Research on Materials, National Institute for Materials Science (NIMS) 2 International Center for Young Scientist (ICYS) ,National Institute for Materials Science (NIMS) The 4DSTEM measurement, which obtains diffraction patterns at each probe position during scanning transmission electron microscopy (STEM), has gained attention due to recent advancements in detectors. Ptychography [1] is a method to derive phase information from 4DSTEM data. This technique is noted for its high beam efficiency and its post correction capability, making it suitable for beam sensitive materials [2]. In this presentation, we will discuss the image features of ptychography. The figure shows the phase reconstructed from datasets of gold nanoparticles obtained under in-focus and 100 nm defocused conditions. Under the 100 nm defocused condition, it is usually challenging to visualize gold particles in conventional STEM images, but ptychography allows for the reconstruction of gold particles by estimating and correcting aberrations from the data. P4-13Deriving Sample Information from 4DSTEM Dataset by Electron Ptychography [1] J.M. Rodenburg and R.H.T. Bates, Phil. Trans. R. Soc. Lond. A, 339, 521(1992).[2] K. Mitsuishi, et al., Sci. Rep., 13, 316 (2023).P4-14Characterization of Aberration-Corrected Lorentz TEM and STEM Yu Jimbo1, Yuto Tomita2, Yuki Ninota1, Kanako Kobayashi1, Takeo Sasaki1, Shigemasa Ohta1,Takehiro Tamaoka2, and Yasukazu Murakami2 [1] Xiuzhen Yu et al, JEOL NEWS, 50, 2-10(2015). [2] Takuro Nagai et al, PHYSICAL REVIEW B, 96, 100405(2017) Lorentz microscopy is one of the powerful observation methods without the influence of magnetic field from the objective lens (OL) of a transmission electron microscope (TEM). Normally, the magnetic field around the TEM specimen is about 2 T. This field could adversely affect the observation of magnetic material. To avoid the influence, OL needs to be turned off and the lens under the OL is used as a focus lens, where it is called an objective mini-lens (OM) in JEOL instrument. We can use the OL to apply some amount of magnetic field to samples in Lorentz microscopy [1]. Recently, the spherical aberration correction was applied to Lorentz microscopy, the resolution was improved [2]. They showed the applied magnetic field with OL is possible with spherical aberration correction. However, the optimum setting for aberration-corrected Lorentz TEM has not been understood yet. In this research, we characterized the detailed capabilities of spherical aberration-corrected Lorentz TEM while applying magnetic field by the OL. On the other hand, spherical aberration correction could be adapted to Lorentz STEM. In STEM case, condenser mini lens is used as focus lens. We confirm the resolution of corrected Lorentz STEM, and the resolution is 0.5nm. In presentation, the detail will be discussed.
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