Uniformly distributed nickel nanoparticles created by heating the carbon nanotube

2003 ◽  
Vol 18 (3) ◽  
pp. 604-608 ◽  
Author(s):  
Zaoli Zhang ◽  
Min Gao
Keyword(s):  
Electron Diffraction ◽  
Nickel Nanoparticles ◽  
Arc Discharge ◽  
Energy Dispersive Spectrometer ◽  
Scanning Transmission Electron Microscope ◽  
Face Centered Cubic ◽  
Transmission Electron ◽  
Nickel Particles ◽  
Scanning Transmission ◽  
Face Centered

Uniformly distributed nanoparticles created by heating carbon nanotubes synthesized by arc-discharge were studied by electron diffraction, high-resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), and x-ray energy dispersive spectrometer (EDS). The nanoparticles have diameters in the range of 3–15 nm. Electron diffraction pattern and HRTEM images analysis both show that the nanoparticles can be nickel or diamond. EELS and EDS analysis in a dedicated scanning transmission electron microscope showed that the nanoparticles are face-centered-cubic nickel particles rather than diamond nanocrystals. The mechanism of formation of nickel nanoparticles below its melting point is discussed.

Description of a New High Resolution Scanning Transmission EM

1972 ◽  
Vol 30 ◽  
pp. 418-419
Author(s):  
Michael Beer ◽  
J. W. Wiggins ◽  
David Woodruff ◽  
Jon Zubin
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Energy Dispersive Spectrometer ◽  
Scanning Transmission Electron Microscope ◽  
Objective Lens ◽  
Condenser Lens ◽  
Transmission Electron ◽  
Pattern Size ◽  
Scanning Transmission ◽  
Under Construction

A high resolution scanning transmission electron microscope of the type developed by A. V. Crewe is under construction in this laboratory. The basic design is completed and construction is under way with completion expected by the end of this year.The optical column of the microscope will consist of a field emission electron source, an accelerating lens, condenser lens, objective lens, diffraction lens, an energy dispersive spectrometer, and three electron detectors. For any accelerating voltage the condenser lens function to provide a parallel beam at the entrance of the objective lens. The diffraction lens is weak and its current will be controlled by the objective lens current to give an electron diffraction pattern size which is independent of small changes in the objective lens current made to achieve focus at the specimen. The objective lens demagnifies the image of the field emission source so that its Gaussian size is small compared to the aberration limit.

scholarly journals Serial protein crystallography in an electron microscope

2019 ◽  
Author(s):  
Robert Bücker ◽  
Pascal Hogan-Lamarre ◽  
Pedram Mehrabi ◽  
Eike C. Schulz ◽  
Lindsey A. Bultema ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Scanning Transmission Electron Microscope ◽  
Dose Fractionation ◽  
X Ray Crystallography ◽  
Minimal Sample ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Alternative Means ◽  
Occlusion Bodies

AbstractSerial X-ray crystallography at free-electron lasers allows to solve biomolecular structures from sub-micron-sized crystals. However, beam time at these facilities is scarce, and involved sample delivery techniques are required. On the other hand, rotation electron diffraction (MicroED) has shown great potential as an alternative means for protein nano-crystallography. Here, we present a method for serial electron diffraction of protein nanocrystals combining the benefits of both approaches. In a scanning transmission electron microscope, crystals randomly dispersed on a sample grid are automatically mapped, and a diffraction pattern at fixed orientation is recorded from each at a high acquisition rate. Dose fractionation ensures minimal radiation damage effects. We demonstrate the method by solving the structure of granulovirus occlusion bodies and lysozyme to resolutions of 1.55 Å and 1.80 Å, respectively. Our method promises to provide rapid structure determination for many classes of materials with minimal sample consumption, using readily available instrumentation.

Digital x-ray mapping of catalyst particles

1984 ◽  
Vol 42 ◽  
pp. 654-655
Author(s):  
C. E. Lyman
Keyword(s):  
Spatial Resolution ◽  
Energy Dispersive Spectrometer ◽  
Scanning Transmission Electron Microscope ◽  
Polished Section ◽  
Early Application ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Early Maps

Formation of 2-dimensional dot maps of x-ray intensity from various elements in a flat polished section was an early application of the scanning beam electron probe microanalyzer. The spatial resolution of those early maps was the same as the microprobe itself, about lpm. These maps were usually scanned in an analogue fashion, and there was generally enough x-ray signal to produce maps with good peak-to-background ratios. For analysis of individual catalyst particles, a scanning transmission electron microscope (STEM) must be used to obtain the required spatial resolution. However, the x-ray signal level is usually low and is collected with an energy-dispersive spectrometer which has a lower peak-to-background ratio than the wavelength-dispersive spectrometer used in the microprobe. To produce suitable high magnification x-ray maps of catalyst particles digital beam techniques were employed.

Energy-filtered electron diffraction from amorphized solids in the dedicated scanning transmission electron microscope (STEM)¶

1996 ◽  
Vol 54 ◽  
pp. 702-703
Author(s):  
A. N. Sreeram ◽  
L.-C. Qin ◽  
A. J. Garratt-Reed ◽  
L. W. Hobbs
Keyword(s):  
Electron Diffraction ◽  
Diffraction Data ◽  
Scanning Transmission Electron Microscope ◽  
Real Space ◽  
Distribution Functions ◽  
Space Distribution ◽  
Electron Diffraction Data ◽  
X Rays ◽  
Transmission Electron ◽  
Scanning Transmission

There is significant current interest in understanding the structure of aperiodic solids, such as originally crystalline material amorphized by ion implantation, impact or application of massive pressures, or deposited amorphous thin films, which occupy small volumes. Radially-averaged real-space distribution functions can be derived from diffraction data, the best of which come from thermal neutron diffraction, which inconveniently requires large volumes. Neutron data are collectable in reciprocal space out to q ≡ 2sin(Θ/2)/λ = 70 nm-1, where Θ is the scattering angle and λ the wavelength, or about twice as far as for X-rays, which also require large diffracting volumes. Electron diffraction is the only recourse for very small volumes because of the much stronger interaction of the electron, but spectra must be energy filtered to remove the large inelastic scattering component. Recently, it has been shown that useful electron diffraction data can be collected conveniently to at least q = 16 nm-1 in the VG HB5 dedicated 100-kV field-emission STEM. This contribution details our experiences with improved collection in the VG HB603 instrument operating at 250 kV.

Research on the Microstructure of Solid FeS by TEM

2011 ◽  
Vol 217-218 ◽  
pp. 1098-1101
Author(s):  
Li Na Zhu ◽  
Cheng Biao Wang ◽  
Hai Dou Wang ◽  
Bin Shi Xu ◽  
Jia Jun Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Transmission Electron Microscope ◽  
Solid Lubricant ◽  
Hexagonal Structure ◽  
Face Centered Cubic ◽  
Transmission Electron ◽  
Different Shapes ◽  
Cubic Structure ◽  
Face Centered

The microstructures of three kinds of synthetical solid FeS, acting as a solid lubricant, which includes FeS bulk, FeS particle and FeS powder, were studied by transmission electron microscope (TEM) in this article. The TEM photographs showed that different shapes of FeS had quite dissimilar characteristics. The texture of FeS powder was the loosest among the three shapes, and it tended to forming flocculent aggregation; while FeS bulk and FeS particle were more dispersive. The electron diffraction results showed that the crystals of solid FeS were composed of many single crystals and multi-crystals, with two kinds of crystalline structure- hexagonal structure and face-centered cubic structure.

On the Determination of Partial RDFs for Amorphous Materials

1993 ◽  
Vol 321 ◽  
Author(s):  
L. C. Qin ◽  
L. W. Hobbs
Keyword(s):  
Electron Diffraction ◽  
Diffraction Data ◽  
Amorphous Materials ◽  
Vitreous Silica ◽  
Scanning Transmission Electron Microscope ◽  
Distribution Functions ◽  
Electron Diffraction Data ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission

ABSTRACTRadial distribution functions (RDFs) for vitreous silica (V-SiO2) have been obtained from energy-filtered electron diffraction data obtained in the HB5 scanning transmission electron Microscope. Results have been compared with those obtained from high-resolution neutron diffraction experiments, and are in good agreement within experimental errors. It was found to be impractical to obtain partial RDFs for this material from combined neutron, X-ray and electron diffraction data, because the similarities in characteristics of X-ray and electron scattering cause indeter-Minacies. A criterion equation has been given to determine feasibility.

An Overview of Dry Sliding Wear of Two-Phase FeNiMnAl Alloys

2012 ◽  
Vol 1516 ◽  
pp. 103-108 ◽  
Author(s):  
Xiaolan Wu ◽  
Fanling Meng ◽  
Ian Baker ◽  
Hong Wu ◽  
Paul R. Munroe
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Energy Dispersive Spectrometer ◽  
Scanning Transmission Electron Microscope ◽  
Dry Sliding Wear ◽  
Two Phase ◽  
Test Environment ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Pin On Disc

ABSTRACTThe pin-on-disc wear behavior of nanostructured two-phase Fe30Ni20Mn20Al30 and eutectic lamellar-structured Fe30Ni20Mn35Al15 is compared emphasizing the influence of the microstructure and mechanical properties of alloys as well as the effect of test environment. Although the wear of both alloys was greater in oxygen-containing environments, eutectic Fe30Ni20Mn35Al15 is less sensitive to oxygen than nanostructured Fe30Ni20Mn20Al30. Abrasive wear dominated during the wear in all cases, while plastic deformation also occurred during the wear of eutectic Fe30Ni20Mn35Al15. A tribolayer of zirconia, which was embedded in the surface of the wear pin, was characterized using a scanning transmission electron microscope equipped with an energy dispersive spectrometer.

Nano-Sized Cuboid-Shaped Phase in Mg–Nd–Y Alloy and its Behavior During Isothermal Aging

2016 ◽  
Vol 22 (6) ◽  
pp. 1244-1250 ◽  
Author(s):  
Jingxu Zheng ◽  
Zhongyuan Luo ◽  
Lida Tan ◽  
Bin Chen
Keyword(s):  
Isothermal Aging ◽  
Lattice Parameter ◽  
Dark Field ◽  
Atomic Scale ◽  
Face Centered Cubic ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Annular Dark Field ◽  
Face Centered ◽  
Image Position

AbstractIn the present study, nano-sized cuboid-shaped particles in Mg–Nd–Y are studied by means of Cs-corrected atomic-scale high-angle annular dark-field scanning transmission electron microscopy. The structure of the cuboid-shaped phase is identified to be yttrium (major component) and neodymium atoms in face-centered cubic arrangement without the participation of Mg. The lattice parameter a=5.15 Å. During isothermal aging at 225°C, Mg3(Nd,Y) precipitates adhere to surface (100) planes of the cuboid-shaped particles with the orientation relationship: $[100]_{{{\rm Mg}_{{\rm 3}} {\rm RE}}} \,/\,\,/\,[100]_{{{\rm Cuboid}}} $ and $[310]_{{{\rm Mg}_{{\rm 3}} {\rm RE}}} \,/\,\,/\,[012]_{{{\rm Cuboid}}} $ . The fully coherent interfaces between the precipitates and the cuboid-shaped phases are reconstructed and categorized into two types: $(400)_{{{\rm Mg}_{{\rm 3}} {\rm RE}}} $ interface and $(200)_{{{\rm Mg}_{{\rm 3}} {\rm RE}}} $ interface.

A microdiffraction study of Os10C(Co)24-2 in the Scanning Transmission Electron Microscope

1986 ◽  
Vol 44 ◽  
pp. 696-697 ◽  
Author(s):  
M. E. Mochel ◽  
R. I. Masel ◽  
J. M. Mochel
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Structural Information ◽  
Carbon Film ◽  
Scanning Transmission Electron Microscope ◽  
Metal Particles ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Small Metal Particles

Recent papers have discussed some of the difficulties in determining the structure of very small (<10Å) metal particles using electron microscopy. One of the ideas in the literature is that electron diffraction could provide structural information even under conditions where imaging is difficult. The purpose of the work reported here is to demonstrate that one can use electron diffraction techniques to obtain structural information about small metal particles, in this case 5Å osmium particles on a carbon film.

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