scholarly journals Dark-field Transmission Electron Microscopy Imaging Technique to Visualize the Local Structure of Two-dimensional Material; Graphene

2015 ◽  
Vol 45 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Min Young Na ◽  
Seung-Mo Lee ◽  
Do Hyang Kim ◽  
Hye Jung Chang
2013 ◽  
Vol 19 (S5) ◽  
pp. 43-48 ◽  
Author(s):  
Maria Rudneva ◽  
Bo Gao ◽  
Ferry Prins ◽  
Qiang Xu ◽  
Herre S.J. van der Zant ◽  
...  

AbstractIn situ transmission electron microscopy was performed on the electromigration in platinum (Pt) nanowires (14 nm thick, 200 nm wide, and 300 nm long) with and without feedback control. Using the feedback control mode, symmetric electrodes are obtained and the gap usually forms at the center of the Pt nanowire. Without feedback control, asymmetric electrodes are formed, and the gap can occur at any position along the wire. The three-dimensional gap geometries of the electrodes in the Pt nanowire were determined using high-angle annular dark-field scanning transmission electron microscopy; the thickness of the nanowire is reduced from 14 nm to only a few atoms at the edge with a gap of about 5–10 nm.


2020 ◽  
Author(s):  
Jin Tang ◽  
Yaodong Wu ◽  
Lingyao Kong ◽  
Weiwei Wang ◽  
Yutao Chen ◽  
...  

Abstract We report differential phase contrast scanning transmission electron microscopy (TEM) of nanoscale magnetic objects in Kagome ferromagnet Fe3Sn2 nanostructures. This technique can directly detect the deflection angle of a focused electron beam, thus allowing clear identification of the real magnetic structures of two magnetic objects including three-ring and complex arch-shaped vortices in Fe3Sn2 by Lorentz transmission electron microscopy imaging. Numerical calculations based on real material-specific parameters well reproduced the experimental results, showing that the magnetic objects can be attributed to integral magnetizations of two types of complex three-dimensional (3D) magnetic bubbles with depth-modulated spin twisting. Magnetic configurations obtained using the high-resolution TEM are generally considered as two-dimensional (2D) magnetic objects previously. Our results imply the importance of the integral magnetizations of underestimated 3D magnetic structures in 2D TEM magnetic characterizations.


2016 ◽  
Vol 361 (1) ◽  
pp. 73-81
Author(s):  
Jeanne Ayache ◽  
Christine Péchoux ◽  
Danielle Jaillard ◽  
Bruno Payré ◽  
Isabelle Pignot-Paintrand ◽  
...  

Microscopy ◽  
2020 ◽  
Author(s):  
Xiaoguang Li ◽  
Kazutaka Mitsuishi ◽  
Masaki Takeguchi

Abstract Liquid cell transmission electron microscopy (LCTEM) enables imaging of dynamic processes in liquid with high spatial and temporal resolution. The widely used liquid cell (LC) consists of two stacking microchips with a thin wet sample sandwiched between them. The vertically overlapped electron-transparent membrane windows on the microchips provide passage for the electron beam. However, microchips with imprecise dimensions usually cause poor alignment of the windows and difficulty in acquiring high-quality images. In this study, we developed a new and efficient microchip fabrication process for LCTEM with a large viewing area (180 µm × 40 µm) and evaluated the resultant LC. The new positioning reference marks on the surface of the Si wafer dramatically improve the precision of dicing the wafer, making it possible to accurately align the windows on two stacking microchips. The precise alignment led to a liquid thickness of 125.6 nm close to the edge of the viewing area. The performance of our LC was demonstrated by in situ transmission electron microscopy imaging of the dynamic motions of 2-nm Pt particles. This versatile and cost-effective microchip production method can be used to fabricate other types of microchips for in situ electron microscopy.


2020 ◽  
Vol 75 (11) ◽  
pp. 913-919
Author(s):  
Frank Krumeich

AbstractSince the 1970s, high-resolution transmission electron microscopy (HRTEM) is well established as the most appropriate method to explore the structural complexity of niobium tungsten oxides. Today, scanning transmission electron microscopy (STEM) represents an important alternative for performing the structural characterization of such oxides. STEM images recorded with a high-angle annular dark field (HAADF) detector provide not only information about the cation positions but also about the distribution of niobium and tungsten as the intensity is directly correlated to the local scattering potential. The applicability of this method is demonstrated here for the characterization of the real structure of Nb7W10O47.5. This sample contains well-ordered domains of Nb8W9O47 and Nb4W7O31 besides little ordered areas according to HRTEM results. Structural models for Nb4W7O31 and twinning occurring in this phase have been derived from the interpretation of HAADF-STEM images. A remarkable grain boundary between well-ordered domains of Nb4W7O31 and Nb8W9O47 has been found that contains one-dimensionally periodic features. Furthermore, short-range order observed in less ordered areas could be attributed to an intimate intergrowth of small sections of different tetragonal tungsten bronze (TTB) based structures.


2010 ◽  
Vol 16 (S2) ◽  
pp. 80-81 ◽  
Author(s):  
SD Findlay ◽  
N Shibata ◽  
H Sawada ◽  
E Okunishi ◽  
Y Kondo ◽  
...  

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.


Sign in / Sign up

Export Citation Format

Share Document