Identification of the misfit dislocations at YBa2Cu3O7−δ/SrTiO3 interface using moiré fringe contrast

2006 ◽  
Vol 444 (1-2) ◽  
pp. 1-4 ◽  
Author(s):  
H. Wang ◽  
S.R. Foltyn ◽  
P.N. Arendt ◽  
Q.X. Jia ◽  
X. Zhang
Keyword(s):  
Misfit Dislocations ◽  
Fringe Contrast ◽  
Moire Fringe ◽  
Moiré Fringe

Simulation and Contrast Analysis of tem Images of Cracks

1990 ◽  
Vol 48 (1) ◽  
pp. 578-579
Author(s):  
D. Goyal ◽  
A. H. King
Keyword(s):  
Displacement Vector ◽  
Crack Tip ◽  
Perfect Crystal ◽  
Operating Conditions ◽  
Displacement Fields ◽  
Fringe Contrast ◽  
Orthogonal Geometry ◽  
Moire Fringe ◽  
Moiré Fringe

TEM images of cracks have been found to give rise to a moiré fringe type of contrast. It is apparent that the moire fringe contrast is observed because of the presence of a fault in a perfect crystal, and is characteristic of the fault geometry and the diffracting conditions in the TEM. Various studies have reported that the moire fringe contrast observed due to the presence of a crack in an otherwise perfect crystal is distinctive of the mode of crack. This paper describes a technique to study the geometry and mode of the cracks by comparing the images they produce in the TEM because of the effect that their displacement fields have on the diffraction of electrons by the crystal (containing a crack) with the corresponding theoretical images. In order to formulate a means of matching experimental images with theoretical ones, displacement fields of dislocations present (if any) in the vicinity of the crack are not considered, only the effect of the displacement field of the crack is considered.The theoretical images are obtained using a computer program based on the two beam approximation of the dynamical theory of diffraction contrast for an imperfect crystal. The procedures for the determination of the various parameters involved in these computations have been well documented. There are three basic modes of crack. Preliminary studies were carried out considering the simplest form of crack geometries, i. e., mode I, II, III and the mixed modes, with orthogonal crack geometries. It was found that the contrast obtained from each mode is very distinct. The effect of variation of operating conditions such as diffracting vector (), the deviation parameter (ω), the electron beam direction () and the displacement vector were studied. It has been found that any small change in the above parameters can result in a drastic change in the contrast. The most important parameter for the matching of the theoretical and the experimental images was found to be the determination of the geometry of the crack under consideration. In order to be able to simulate the crack image shown in Figure 1, the crack geometry was modified from a orthogonal geometry to one with a crack tip inclined to the original crack front. The variation in the crack tip direction resulted in the variation of the displacement vector also. Figure 1 is a cross-sectional micrograph of a silicon wafer with a chromium film on top, showing a crack in the silicon.

Simulation of dislocations imaged moiré fringe contrast

1993 ◽  
Vol 24 (2) ◽  
pp. 185-192 ◽  
Author(s):  
James E. Angelo ◽  
W. W. Gerberich
Keyword(s):  
Fringe Contrast ◽  
Moire Fringe ◽  
Moiré Fringe

A Study of FeAl/AlAs/GaAs Interfaces Using Moiré-Fringe Contrast in a Transmission Electron Microscope

1990 ◽  
Vol 202 ◽  
Author(s):  
J. E. Angelo ◽  
J.N. Kuznia ◽  
A.M. Wowchak ◽  
P. I. Cohen ◽  
W. W. Gerberich
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Growth Temperature ◽  
Growth Mode ◽  
Misfit Dislocations ◽  
Layer By Layer ◽  
Plan View ◽  
Transmission Electron ◽  
Moire Fringe ◽  
Moiré Fringe

ABSTRACTThis paper describes the transmission electron microscope (TEM) investigations of the defect structure present at various FeAl/AlAs/GaAs interfaces. Although a systematic study has not yet been completed it is shown that by changing the growth temperature from 200°C to 300°C the growth morphology changes significantly. In-situ RHEED studies show the growth mode changes from layer-by-layer to island-like when the growth temperature is increased. TEM in both plan-view and cross-sectional modes is used to confirm these results. It is found that by increasing the growth temperature from 200°C to 300°C the growth mode switches from layer-by-layer (2D) with a continuous FeAl film, to island-like (3D) with significant numbers of “pin-holes”. A Moiré-fringe analysis is applied to determine the Burgers vector of the misfit dislocations. In both cases the interface between the FeAl and AlAs consists of a grid of misfit dislocations with [100] and [010] line directions whose Burgers vectors are [010] and [100] respectively.

An automatic high-speed scanner for moiré fringe techniques

1972 ◽  
Vol 7 (2) ◽  
pp. 151-156 ◽  
Author(s):  
D J Hitchings ◽  
A R Luxmoore
Keyword(s):  
High Speed ◽  
Peak Detection ◽  
Optical Signal ◽  
Single Line ◽  
Scanning System ◽  
Moiré Fringes ◽  
Moire Fringe ◽  
Scanning Line ◽  
Moiré Fringe

A high-speed scanning system has been developed to locate the centres of moiré fringes along any single line. The system comprises a rotating-mirror scanner for conversion of an optical signal to electrical; this conversion is followed by peak detection, storage, and print-out electronics. Up to 20 fringes can be scanned in 1 ms. The results are printed in terms of fringe separations along the scanning line.

scholarly journals Reproducible strain measurement in electronic devices by applying integer multiple to scanning grating in scanning moiré fringe imaging

AIP Advances ◽  
2014 ◽  
Vol 4 (10) ◽  
pp. 107107 ◽  
Author(s):  
Suhyun Kim ◽  
Younheum Jung ◽  
Joong Jung Kim ◽  
Sunyoung Lee ◽  
Haebum Lee ◽  
...  
Keyword(s):  
Strain Measurement ◽  
Electronic Devices ◽  
Integer Multiple ◽  
Moire Fringe ◽  
Moiré Fringe
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