![]() ![]() 1(a), the rows of silicon atoms with a spacing of 0.136 nm (silicon dumbbells) are observed only as a single bright spot (ellipse), but in the image of Fig. 1 shows a high-angle annular dark-field STEM (HAADF-STEM) image of a silicon crystal observed from the <110> direction with Cs-corrector or not. As a result, a low-noise STEM image can be acquired in about 1/10 of the conventional time, and the effect of sample drift can be reduced.įig. In addition, the Cs corrector has the advantage of increasing the intensity of the electron probe. It is possible to form a narrow electron probe than before and achieve STEM observation with ultra-high spatial resolution of 0.1 nm or less using Cs-corrector. The resolution of a scanning transmission electron microscope (STEM) image depends on the electron probe size. High resolution STEM observation using aberration-corrected probe ■Measurement of carbon materials by low acceleration voltage.■High-sensitivity EDX measurement using a large-aperture SDD detector.■High energy resolution EELS using Cold-FEG.■High resolution STEM observation using aberration-corrected probe.2, the current value of the electron probe after aberration correction increases by about one order of magnitude compared to that before aberration correction. ![]() Therefore, the electron beam can be focused to a more localized area on the sample surface, and a narrow electron probe can be formed.Īs shown in Fig. On the other hand, if a concave lens (Cs-corrector) is introduced below the convex lens, this difference in the amount of refraction can be successfully counteracted. Electron beams passing away from the center of the lens are refracted to a greater extent, so the electron beam does not normally converge to a single point on the sample surface, and the electron probe size expands. 1 shows the difference in the electron beam path diagram with and without the aberration correction mechanism in the probe system. Cs-corrected STEM can locate and identify elements at the single atom level.įig. By incorporating this Cs-corrector into the systems of the TEM, a resolution of 0.1 nm, which could not be achieved with the conventional TEM, was achieved. The devices made it possible to improve lens aberration by combining a concave lens and a convex lens like an optical microscope. However, in recent years, a device (Cs-corrector) has been developed that realizes a concave lens using the theoretically proposed multipoles. Therefore, the resolution was limited by various aberrations of the lens, especially the third-order spherical aberration (Cs). In principle, only convex lenses can be made for the magnetic field lenses used in electron microscopes. Transmission electron microscopy (TEM) has made remarkable progress due to the development of aberration correction technology nowadays. Spherical aberration corrected Scanning Transmission Electron Microscope:Cs-corrected STEM What’s the aberration correction function? ![]()
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