The use of through focus exit wave reconstruction and quantitative electron diffraction in the structure determination of superconductors

The feasibility of the through focus exit wave reconstruction method and its most important limitations are discussed. It is shown that combination of the amplitude and phase information of the exit waves at various thicknesses allows one to determine the positions of all atoms. Whereas the light atoms can be best distinguished in the phase image of a somewhat thicker part of a crystal, the heavy atoms can be observed most reliably in the amplitude part. In particular the change of the exit wave with thickness was found to be very useful in the determination of the presence of light atoms. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.