Determination of the Nature of Neutron Irradiation-Induced Dislocation Loops in Magnesium Using Electron Irradiation in the Transmission Electron Microscope

2009 ◽  
pp. 5-5-7
Author(s):  
A Wolfenden
Keyword(s):  
Electron Microscope ◽  
Neutron Irradiation ◽  
Transmission Electron Microscope ◽  
Electron Irradiation ◽  
Dislocation Loops ◽  
Transmission Electron ◽  
Induced Dislocation

Direction of Black-White Contrast from Small Dislocation Loops

1977 ◽  
Vol 35 ◽  
pp. 56-57
Author(s):  
W. D. Cooper ◽  
C. S. Hartley ◽  
J. J. Hren
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Image Plane ◽  
Dislocation Loops ◽  
Burgers Vector ◽  
Simple Concept ◽  
Transmission Electron ◽  
Vector Projection ◽  
Shear Component

Dislocation loops observed in the transmission electron microscope exhibit a characteristic black-white strain contrast under two-beam dynamical diffracting conditions. A simple concept of the nature of this contrast indicates that the black-white direction should lie parallel to the projection of the Burgers vector onto the image plane. Using the results of several contrast calculations for small loops, Wilkens and Riihle (1972) recognized that the black-white direction did not always lie parallel to the Burgers vector projection. For loops with an appreciable shear component, they concluded that a determination of the black-white direction would not be sufficient for analysis of the loop crystallography. However, for pure edge loops they predicted that the black-white direction would correspond (within a few degrees) to the projection of the Burgers vector. Numerous investigators have used this erroneous assumption to analyze the crystallography of loops.

scholarly journals Meso-Scale Transmission Electron Microscope Tomography Applied for Wax Distribution in Toner Particles

2013 ◽  
Vol 19 (S5) ◽  
pp. 58-61 ◽  
Author(s):  
Mino Yang ◽  
Jun-Ho Lee ◽  
Hee-Goo Kim ◽  
Euna Kim ◽  
Young-Nam Kwon ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Three Dimensional ◽  
Chromatic Aberration ◽  
Laser Printer ◽  
Medium Voltage ◽  
Transmission Electron ◽  
Z Contrast ◽  
Contrast Image

AbstractDistribution of wax in laser printer toner was observed using an ultra-high-voltage (UHV) and a medium-voltage transmission electron microscope (TEM). As the radius of the wax spans a hundred to greater than a thousand nanometers, its three-dimensional recognition via TEM requires large depth of focus (DOF) for a volumetric specimen. A tomogram with a series of the captured images would allow the determination of their spatial distribution. In this study, bright-field (BF) images acquired with UHV-TEM at a high tilt angle prevented the construction of the tomogram. Conversely, the Z-contrast images acquired by the medium-voltage TEM produced a successful tomogram. The spatial resolution for both is discussed, illustrating that the image degradation was primarily caused by beam divergence of the Z-contrast image and the combination of DOF and chromatic aberration of the BF image from the UHV-TEM.

Photoluminescence of 10H-SiC

2016 ◽  
Vol 858 ◽  
pp. 269-273
Author(s):  
Anne Henry ◽  
Hiroshi Yano ◽  
Tomoaki Hatayama
Keyword(s):  
Electron Microscope ◽  
Band Gap ◽  
Transmission Electron Microscope ◽  
Lower Energy ◽  
Free Exciton ◽  
Binding Energies ◽  
Photoluminescence Spectra ◽  
Transmission Electron ◽  
First Time

The photoluminescence of the near band gap emission of 10H-SiC is revealed for the first time and detected just below 3.0 eV. The crystallinity thus polytype of the sample is controlled with transmission electron microscope analyses and Laue diffraction. On the photoluminescence spectra up to eight sharp lines are associated to the non-phonon lines of the nitrogen bound exciton even if ten are expected in 10H-SiC. Phonon replicas of these non-phonon lines are observed at lower energy with energy separations similar than those in other hexagonal SiC polytypes. At moderate temperature free-exciton replicas are also observed which allow the determination of the excitonic band gap at 3020.6 meV, value in agreement with the hexagonality of 10H-SiC of 40%. The binding energies associated to the nitrogen bound-excitons are determined as well as the ionization energies of the nitrogen donors in the 10H-SiC polytype.

Crystalline to Amorphous Transformation of Fe3B By 1 MeV Electron Irradiation

1981 ◽  
Vol 7 ◽  
Author(s):  
A. Mogro-Campero ◽  
E.L. Hall ◽  
J.L. Walter ◽  
A.J. Ratkowski
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Electron Irradiation ◽  
Room Temperature ◽  
Ion Irradiation ◽  
Rapid Quenching ◽  
Al Alloy ◽  
Bright Field ◽  
Transmission Electron ◽  
Diffraction Patterns

ABSTRACTSpecimens of amorphous Fe75B25 produced by rapid quenching from the melt were annealed to complete crystallization and subjected to 1 MeV electron irradiation in a transmission electron microscope at room temperature and at 130 K. The irradiation was interrupted at various intervals in order to obtain bright field images and diffraction patterns. The Fe3B crystals did not become amorphous at room temperature, even after damage levels of several dpa, whereas at 130 K the crystalline to amorphous transformation was observed to be complete at damage levels below 1 dpa. The results are combined with those of ion irradiation work on Fe3B; qualitative agreement is found between Fe3B and previous work on the Zr3Al alloy concerning their response to displacement damage by electron and ion irradiation.

A Hvem Study of the Electron Irradiated Defects in Nitrogen Doped FZ-Si Single Crystal

1989 ◽  
Vol 163 ◽  
Author(s):  
Gao Yuzun ◽  
T. Takeyama
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Electron Irradiation ◽  
Defect Density ◽  
Migration Energy ◽  
Nitrogen Doped ◽  
Temperature Range ◽  
Transmission Electron ◽  
Excellent Property ◽  
P Type

AbstractHigh voltage transmission electron microscope (JEM-1000) has been used to investigate the electron irradiated defects in in p-type FZ-Si and nitrogen doped p-type FZ-Si. It was found that when the irradiated conditions were the saie ,the irradiated defects were easier to be produced in the FZ-Si than in nitrogen doped FZ-Si in the temperature range 573-773 K. The defect density was higher in the foraer. The migration energy of the vacancies in the temperature range 573-773 K was 0.34 and 0.58 eV for FZ-Si and nitrogen doped FZ-Si respectively. It seems to indicate that there was some interaction between vacancies and nitrogen atoms in the nitrogen doped FZ-Si. The results proved that the nitrogen doped FZ-Si has excellent property against electron irradiation.

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