Novel method for the synthesis of thin film coatings on particulate materials

1999 ◽  
Vol 14 (8) ◽  
pp. 3281-3291 ◽  
Author(s):  
J. M. Fitz-Gerald ◽  
R. K. Singh ◽  
H. Gao ◽  
D. Wright ◽  
M. Ollinger ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particulate Material ◽  
Thin Film Coatings ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Novel Method ◽  
Nanoparticle Coatings ◽  
Z Contrast ◽  
Core Particles

In this paper, we show the feasibility of the pulsed-laser ablation technique to grow 20–30-nm-thick, discrete and continuous coatings on particulate material systems so that the properties of the core particles can be suitably modified. Experiments were conducted with a pulsed excimer laser (λ = 248 nm, pulse duration = 25 ns) to deposit nanoparticle coatings on Al2O3 and SiO2 core particles by irradiation of Ag and Y2O3–Eu3+ sputtering targets. Structural characterization was performed with scanning electron microscopy, wavelength dispersive x-ray mapping, transmission electron microscopy, and scanning transmission electron microscopy with z-contrast.

TEM Z-contrast imaging with wide-angle hollow-cone illumination

1990 ◽  
Vol 48 (4) ◽  
pp. 400-401
Author(s):  
J. Bentley ◽  
K. B. Alexander ◽  
Z. L. Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dark Field ◽  
Wide Angle ◽  
Hollow Cone ◽  
Contrast Imaging ◽  
Field Mode ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Z Contrast

High resolution scanning transmission electron microscopy (STEM) images with contrast sensitive to atomic number (Z-contrast) have been obtained with the use of a high-angle annular detector. The equivalent conventional transmission electron microscopy (TEM) dark-field mode reciprocally related to Z-contrast STEM is wide-angle hollow-cone illumination with an on-axis objective aperture. There are two ways to obtain hollow cone illumination; with an annular condenser aperture or by conically scanning the beam tilt coils. As in the case of STEM Z-contrast imaging, resolution with hollow-cone illumination should theoretically be higher than for phase contrast imaging in the same instrument.Philips CM30/STEM, CM12/STEM, and EM400T/FEG/STEM instruments have been used to investigate this imaging technique. The conical illumination dark-field mode is standard on the CM series and was implemented with a hybrid diffraction unit on the EM400. Commercial (SPI Supplies #1780) copper annular apertures with inner and outer diameters of 600 and 900 μm, respectively, spot welded to suitable supports for use as condenser apertures, resulted in cone angles too small to give good Z-contrast in the microprobe mode, because there is still a large diffraction contrast contribution.

Aberration-corrected scanning transmission electron microscopy: from atomic imaging and analysis to solving energy problems

2009 ◽  
Vol 367 (1903) ◽  
pp. 3709-3733 ◽  
Author(s):  
S. J. Pennycook ◽  
M. F. Chisholm ◽  
A. R. Lupini ◽  
M. Varela ◽  
A. Y. Borisevich ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Single Atom ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Z Contrast ◽  
Contrast Image ◽  
Aberration Corrected

The new possibilities of aberration-corrected scanning transmission electron microscopy (STEM) extend far beyond the factor of 2 or more in lateral resolution that was the original motivation. The smaller probe also gives enhanced single atom sensitivity, both for imaging and for spectroscopy, enabling light elements to be detected in a Z-contrast image and giving much improved phase contrast imaging using the bright field detector with pixel-by-pixel correlation with the Z-contrast image. Furthermore, the increased probe-forming aperture brings significant depth sensitivity and the possibility of optical sectioning to extract information in three dimensions. This paper reviews these recent advances with reference to several applications of relevance to energy, the origin of the low-temperature catalytic activity of nanophase Au, the nucleation and growth of semiconducting nanowires, and the origin of the eight orders of magnitude increased ionic conductivity in oxide superlattices. Possible future directions of aberration-corrected STEM for solving energy problems are outlined.

scholarly journals Nucleoid Structure of Escherichia coli as Revealed by Scanning Transmission Electron Microscopy (STEM) and by 3D-Reconstruction of Z-Contrast Images of Serial Sections

2013 ◽  
Vol 19 (S2) ◽  
pp. 144-145
Author(s):  
B. Reiner ◽  
Y. Guo ◽  
E.W. Roth ◽  
N.H. Yazdi ◽  
R.C. Johnson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Transmission Electron Microscopy ◽  
3D Reconstruction ◽  
Scanning Transmission Electron Microscopy ◽  
Serial Sections ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Nucleoid Structure ◽  
Z Contrast

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

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