Etude théorique de la propagation des électrons rapides dansles alliages: application à la microscopie électronique en transmission

Abstract : Theoretical study of the propagation of high energy electrons in
substitutional alloys: application to Transmission Electron
Microscopy.

This work is dealing with the effect of substitutionnal disorder on the propagation of high energy electrons. Some recent observations from electron microscopists tend to show that, the relation between the electronic density and the atomic potential, could be highly non-linear in some cases. The aim of this work is therefore to give a
precise characterization of the effect of chemical disorder on the exit wave function
in Transmission Electron Microscopy.

A very precise analysis of simple cases (diffraction by simple monoatomic structures,
and by ordered alloys) was first made in order to understand clearly the {\sl phenomena}, and to find the relevant physical parameters of the problem. Once this analysis was made t was easier to tackle the difficult problem of chemical disorder. The systematic use of the so called Atomic Column Approximation'' first derived by Dirk Van Dyck allowed us to describe in a simple and concise manner the effect of chemical disorder. Our formalism can explain a wide range of experimental observations, but it also opens new possibilities for the application to complex {\sl phenomena} such as diffuse scattering, or effect of thermal vibrations, and it could be applied to numerous experimental situations.
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https://tel.archives-ouvertes.fr/tel-00002096
Contributor : Cyrille Barreteau <>
Submitted on : Monday, December 9, 2002 - 3:36:30 PM
Last modification on : Friday, March 5, 2021 - 3:12:03 PM
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• HAL Id : tel-00002096, version 1

Citation

Cyrille Barreteau. Etude théorique de la propagation des électrons rapides dans
les alliages: application à la microscopie électronique en transmission. Physique [physics]. Université Pierre et Marie Curie - Paris VI, 1995. Français. ⟨tel-00002096⟩

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