The NCEM One-Angstrom Microscope Project Reaches 0.89Å Resolution

2000 ◽  
Vol 6 (S2) ◽  
pp. 1192-1193 ◽  
Author(s):  
Michael A. O'Keefe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Image Reconstruction ◽  
Structural Information ◽  
Computer Software ◽  
Image Simulation ◽  
Resolution Limit ◽  
Transmission Electron ◽  
Better Than

Transmission electron microscopy to a resolution of 0.89Å has been achieved at the National Center for Electron Microscopy and is available to electron microscopists who have a requirement for this level of resolution. Development of this capability commenced in 1993, when the National Center for Electron Microscopy agreed to fund a proposal for a unique facility, a one- Ångstrom microscope (OÅM).2 The OÅM project provides materials scientists with transmission electron microscopy at a resolution better than one Angstrom by exploiting the significantly higher information limit of a FEG-TEM over its Scherzer resolution limit. To turn the misphased information beyond the Scherzer limit into useful resolution, the OÅM requires extensive image reconstruction. One method chosen was reconstruction from off-axis holograms; another was reconstruction from focal series of underfocused images. The OÅM is then properly a combination of a FEG-TEM (a CM300FEG-UT) together with computer software able to generate sub-Ångstrom images from experimental images obtained on the FEG-TEM.Before the advent of the OÅM, NCEM microscopists relied on image simulation to obtain structural information beyond the TEM resolution limit.

A method of precise misorientation determination

2003 ◽  
Vol 36 (6) ◽  
pp. 1319-1323 ◽  
Author(s):  
A. Morawiec
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Spatial Resolution ◽  
Standard Procedure ◽  
Good Spatial Resolution ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Achievable Accuracy ◽  
Better Than

A method that improves the accuracy of misorientations determined from Kikuchi patterns is described. It is based on the fact that some parameters of a misorientation calculated from two orientations are more accurate than other parameters. A procedure which eliminates inaccurate elements is devised. It requires at least two foil inclinations. The quality of the approach relies on the possibility to set large sample-to-detector distances and the availability of good spatial resolution of transmission electron microscopy. Achievable accuracy is one order of magnitude better than the accuracy of the standard procedure.

Three-Dimensional Dispersion of Nano-Fillers in Soft Composite as Revealed by Transmission Electron Microscopy/Electron Tomography (3D-TEM)

2006 ◽  
Vol 514-516 ◽  
pp. 353-358 ◽  
Author(s):  
Shinzo Kohjiya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Natural Rubber ◽  
Structural Information ◽  
Electron Tomography ◽  
Nano Composites ◽  
Nano Structure ◽  
Transmission Electron ◽  
Particulate Silica

. Generally rubber products are a typical soft material, and a composite of a nano-filler (typically, carbon black or particulate silica) and a rubber (natural rubber and various synthetics are used). The properties of these soft nano-composites have been well known to depend on the dispersion of the nano-filler in the rubbery matrix. The most powerful tool for the elucidation of it has been transmission electron microscopy (TEM). The microscopic techniques are based on the projection of 3-dimensional (3D) body on a plane (x, y plane), thus the structural information along the thickness (z axis) direction of the sample is difficult to obtain. This paper describes our recent results on the dispersion of carbon black (CB) and particulate silica in natural rubber (NR) matrix observed by TEM combined with electron tomography (3D-TEM) technique, which enabled us to obtain images of 3D nano-structure of the sample. Thus, 3D images of CB and silica in NR matrix are visualized and analyzed in this communication. These results are precious ones for the design of soft nano-composites, and the technique will become an indispensable one in nanotechnology.

Transmission Electron Microscopy Studies of Strained Si CMOS

2005 ◽  
Vol 864 ◽  
Author(s):  
Qianghua Xie ◽  
Peter Fejes ◽  
Mike Kottke ◽  
Xiangdong Wang ◽  
Mike Canonico ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Structural Information ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Strained Si ◽  
Thermal Budget ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractIn this paper, various types of defects (both threading dislocation and misfit dislocations) in strained Si (sSi) have been analyzed by transmission electron microscopy (TEM). Germanium upper-diffusion has been studied by scanning transmission electron microscopy (STEM) for strained Si on SiGe/SOI. SGOI-devices processed using an optimized thermal budget show minimal Ge diffusion and minimal process related defects. Correlation between the device performance (such as leakage current and reliability) and structural information found in TEM has been established.

scholarly journals Quantitative Image Simulation for Scanning Transmission Electron Microscopy

2008 ◽  
Vol 14 (S2) ◽  
pp. 930-931
Author(s):  
MP Oxley ◽  
K van Benthem ◽  
SJ Pennycook
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
New Mexico ◽  
Scanning Transmission Electron Microscopy ◽  
Image Simulation ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Quantitative Image ◽  
Scanning Transmission

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

scholarly journals Single-particle cryo-EM: alternative schemes to improve dose efficiency

2021 ◽  
Vol 28 (5) ◽  
pp. 1343-1356
Author(s):  
Yue Zhang ◽  
Peng-Han Lu ◽  
Enzo Rotunno ◽  
Filippo Troiani ◽  
J. Paul van Schayck ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Radiation Damage ◽  
Information Transfer ◽  
Structural Information ◽  
High Energy ◽  
Phase Plate ◽  
Transmission Electron ◽  
Dose Efficiency ◽  
The Individual

Imaging of biomolecules by ionizing radiation, such as electrons, causes radiation damage which introduces structural and compositional changes of the specimen. The total number of high-energy electrons per surface area that can be used for imaging in cryogenic electron microscopy (cryo-EM) is severely restricted due to radiation damage, resulting in low signal-to-noise ratios (SNR). High resolution details are dampened by the transfer function of the microscope and detector, and are the first to be lost as radiation damage alters the individual molecules which are presumed to be identical during averaging. As a consequence, radiation damage puts a limit on the particle size and sample heterogeneity with which electron microscopy (EM) can deal. Since a transmission EM (TEM) image is formed from the scattering process of the electron by the specimen interaction potential, radiation damage is inevitable. However, we can aim to maximize the information transfer for a given dose and increase the SNR by finding alternatives to the conventional phase-contrast cryo-EM techniques. Here some alternative transmission electron microscopy techniques are reviewed, including phase plate, multi-pass transmission electron microscopy, off-axis holography, ptychography and a quantum sorter. Their prospects for providing more or complementary structural information within the limited lifetime of the sample are discussed.

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