Open AccessNew Features of Dislocation Images in Third‐Generation Synchrotron Radiation Topographs
Author(s) -
Zontone F.,
Mancini L.,
Barrett R.,
Baruchel J.,
Härtwig J.,
Epelboin Y.
Publication year - 1996
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049596002269
Subject(s) - monochromatic color , synchrotron radiation , burgers vector , optics , beam (structure) , dislocation , diffraction , physics , plane wave , synchrotron , resolution (logic) , image resolution , materials science , angular resolution (graph drawing) , computational physics , condensed matter physics , mathematics , computer science , combinatorics , artificial intelligence , transmission electron microscopy
Some aspects of the dislocation contrast observed at third‐generation synchrotron radiation set‐ups are presented. They can be explained by taking into account angular deviation effects on the beam propagation, which are visible because of the `almost plane‐wave' character of these sources. In particular, we show how the evolution of the direct image width of a dislocation as a function of the sample‐to‐film distance can allow a complete determination of the Burgers vector, i.e. in sign and modulus. In addition, experimental results obtained in monochromatic beam topography are compared with simulated images calculated assuming plane‐wave illumination and are demonstrated to show a satisfactory agreement. The utility of the weak‐beam technique in enhancing the spatial resolution is demonstrated and a criterion for the selection of experimental conditions depending upon the required spatial resolution, signal‐to‐noise ratio and exposure time is presented.