Applications of the Oxford-JEOL aberration-corrected electron microscope

Formation of Klein Edge Doublets from Graphene Monolayers

“…CVD graphene specimens supported by SiN grids were heated for approximately 24 h just prior to TEM observation at 180 °C and 1 × 10 –3 Pa in order to remove residual hydrocarbons. Aberration-corrected TEM images were collected at room temperature using a double-aberration-corrected JEOL 2200MCO − operated at 80 kV acceleration voltage. Although equipped with a monochromator that can enhance images by removing chromatic effects, this work was done with the monochromator turned off for higher electron current density micrographs.…”

“…36,37 Experimental aberration corrected transmission electron microscopy (AC-TEM) images were recorded at room temperature using a JEOL 2200MCO [38][39][40] at 80 kV acceleration voltage, beneath the sputtering knock-on damage threshold for sp 2 bonded carbon. 41,42 Experimental AC-TEM imaging conditions were collected using optimized negative spherical aberration, C 3 , imaging conditions 43 (see also Methods).…”

“…Monolayer graphene was produced by atmospheric chemical vapor deposition (CVD) over a heated Cu substrate and subsequently removed using a FeCl 3 etchant and transferred to a perforated Si 3 N 4 support grid using a poly(methyl methacrylate) (PMMA) scaffold. , Experimental aberration-corrected transmission electron microscopy (AC-TEM) images were recorded at room temperature using a JEOL 2200MCO − at 80 kV acceleration voltage, beneath the sputtering knock-on damage threshold for sp 2 -bonded carbon. , Experimental AC-TEM imaging conditions were collected using optimized negative spherical aberration, C 3 , imaging conditions (see also Methods). Edges were created for the study by high current density electron beam irradiation of the target area …”

Direct imaging of light elements by annular dark-field aberration-corrected scanning transmission electron microscopy

“…Nowadays, many crystalline lattices can be imaged directly at atomic resolution in Cs-corrected scanning TEM (STEM) with bright-field (BF) or annular BF (ABF) detectors as well as with annular dark-field (ADF) or with highangle ADF (HAADF) detectors. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] The locations of atomic columns in the ADF images are represented by bright spots on dark background, whereas the positions of atomic columns in the ABF micrographs appear as dark spots on white background. The intensity of BF images depends strongly on the defocus sign as in phase contrast TEM.…”

“…2 In recent years, much instrumental and methodological effort has been put forward in developing of methods for direct imaging of light elements inside various technologically important materials using transmission electron microscopy (TEM). [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] The realization and implementation of spherical aberration (Cs) correction for a round magnetic lens in TEM 19,20 have pushed the instrumental resolution limit of the TEMs down to the sub-Å ngstrom scale. 21,22 In addition, significant improvement of image contrast and signal to noise ratio has been achieved with Cs-corrected TEMs.…”