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Focal-Series Reconstruction in Low-Energy Electron Microscopy

Published online by Cambridge University Press:  09 April 2014

Thomas Duden ,
Andreas Thust ,
Christian Kumpf  and
F. Stefan Tautz
Thomas Duden*
Affiliation:
Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425 Jülich, Germany
Andreas Thust
Affiliation:
Ernst Ruska-Centrum (ER-C) and Peter Grünberg Institut (PGI-5), Forschungszentrum Jülich, 52425 Jülich, Germany Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425 Jülich, Germany
Christian Kumpf
Affiliation:
Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425 Jülich, Germany
F. Stefan Tautz
Affiliation:
Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany Jülich Aachen Research Alliance (JARA)-Fundamentals of Future Information Technology, 52425 Jülich, Germany
*
*Corresponding author. [email protected]
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Abstract

In low-energy electron microscopy (LEEM) we commonly encounter images which, beside amplitude contrast, also show signatures of phase contrast. The images are usually interpreted by following the evolution of the contrast during the experiment, and assigning gray levels to morphological changes. Through reconstruction of the exit wave, two aspects of LEEM can be addressed: (1) the resolution can be improved by exploiting the full information limit of the microscope and (2) electron phase shifts which contribute to the image contrast can be extracted. In this article, linear exit wave reconstruction from a through-focal series of LEEM images is demonstrated. As a model system we utilize a heteromolecular monolayer consisting of the organic molecules 3,4,9,10-perylene tetracarboxylic dianhydride and Cu-II-Phthalocyanine, adsorbed on a Ag(111) surface.

Keywords

low-energy electron microscopy (LEEM)phase contrast imagingphase retrieval
Type
Techniques and Instrumentation Development
Information
Microscopy and Microanalysis , Volume 20 , Issue 3 , June 2014 , pp. 968 - 973
Copyright
© Microscopy Society of America 2014 

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