Ultramicroscopy 2011-06-01

Applying an information transmission approach to extract valence electron information from reconstructed exit waves.

Qiang Xu, Henny W Zandbergen, Dirk Van Dyck, Qiang Xu, Henny W. Zandbergen, Dirk Van Dyck

Index: Ultramicroscopy 111(7) , 912-9, (2011)

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Abstract

The knowledge of the valence electron distribution is essential for understanding the properties of materials. However this information is difficult to obtain from HREM images because it is easily obscured by the large scattering contribution of core electrons and by the strong dynamical scattering process. In order to develop a sensitive method to extract the information of valence electrons, we have used an information transmission approach to describe the electron interaction with the object. The scattered electron wave is decomposed in a set of basic functions, which are the eigen functions of the Hamiltonian of the projected electrostatic object potential. Each basic function behaves as a communication channel that transfers the information of the object with its own transmission characteristic. By properly combining the components of the different channels, it is possible to design a scheme to extract the information of valence electron distribution from a series of exit waves. The method is described theoretically and demonstrated by means of computer simulations.Copyright © 2011 Elsevier B.V. All rights reserved.