Universal relation between electron channeling line intensity and thickness of disordered layers on single crystals

1988 ◽  
Vol 53 (16) ◽  
pp. 1486-1488 ◽  
Author(s):  
Tadashi Suzuki ◽  
Yoshiaki Kido
Keyword(s):  
Single Crystals ◽  
Line Intensity ◽  
Universal Relation ◽  
Electron Channeling

The effects of modulation frequency and rf ENDOR power on 53Cr3+ ENDOR lines in CsAl sulfate alum

1980 ◽  
Vol 58 (5) ◽  
pp. 687-692 ◽  
Author(s):  
A. Manoogian ◽  
B. W. Chan
Keyword(s):  
Single Crystals ◽  
Line Intensity ◽  
Modulation Frequency ◽  
Spectral Lines ◽  
Double Quantum ◽  
Frequency Interpretation ◽  
Lorentzian Form

An investigation was made of the effects of modulation frequency and rf ENDOR power on the single and double quantum ENDOR spectral lines of 53Cr3+ ions in single crystals and powders of CsAl sulfate alum. Measurements were made of the linewidths and intensities in the single crystals and of the linewidths in the powders. It was found in the single crystals that a factor of 2/1 exists for the ratio of single/double quantum linewidths at the limit of zero ENDOR power and modulation frequency. Interpretation of the line intensity results with the results of lineshape theory indicates that the ENDOR lines are of Lorentzian form, at least for low values of ENDOR power.

Direct Characterization of Various Deformation Microstructures in Metals by Electron Channeling Contrast Technique in SEM

2009 ◽  
Vol 79-82 ◽  
pp. 215-218
Author(s):  
Xiao Wu Li
Keyword(s):  
Single Crystals ◽  
Austenitic Stainless Steels ◽  
Wide Field ◽  
Deformation Bands ◽  
Electron Channeling ◽  
Angular Pressing ◽  
Contrast Technique ◽  
Research Findings ◽  
Micro Features

Recent research findings on the electron channeling contrast (ECC) characterization of various deformation microstructures in some metals were summarized. It is shown that the ECC technique can easily image, in a wide field of view, typical dislocation structures in fatigued Cu single crystals, as well as the relevant dislocation arrangements in deformation bands (DBs). The thermal instability of cyclic deformation induced dislocation structures in Cu single crystals under annealing, and microstructural instability of ultrafine-grained (UFG) Cu produced by equal channel angular pressing (ECAP) under annealing or deforming were also well detected by ECC observations. In addition, a trial observation of the plastic deformation micro-features around the fatigue crack (tip) in Al6XN super-austenitic stainless steels was also made by the ECC technique.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

The Microstructure of Shock-Synthesized Diamond

1967 ◽  
Vol 25 ◽  
pp. 324-325
Author(s):  
Lucien F. Trueb
Keyword(s):  
Single Crystals ◽  
Preferred Orientation ◽  
High Magnification ◽  
Texture Pattern ◽  
Shock Process ◽  
New Type ◽  
Diffraction Diagram

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.

A New Defect in Polyethylene Single Crystals

1973 ◽  
Vol 31 ◽  
pp. 70-71
Author(s):  
E. L. Thomas ◽  
S. L. Sass
Keyword(s):  
Single Crystals ◽  
Screw Dislocation ◽  
Small Distance ◽  
Dipole Model ◽  
Dislocation Dipole ◽  
Chain Folding ◽  
Black And White ◽  
Polymer Crystal ◽  
Different Types

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.

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