AVS 47th International Symposium
    Processing at the Nanoscale/NANO 6 Friday Sessions
       Session NS+NANO6+MC-FrM

Paper NS+NANO6+MC-FrM7
Imaging of Single Molecules by Low Energy Electron Point Source Microscopy

Friday, October 6, 2000, 10:20 am, Room 302

Session: Nanoscale Spectroscopy
Presenter: A. Eisele, Universität Heidelberg, Germany
Authors: A. Eisele, Universität Heidelberg, Germany
B. Völkel, Universität Heidelberg, Germany
S. Rehbein, Universität Göttingen, Germany
B. Jäger, Universität Heidelberg, Germany
H.J. Kreuzer, Dalhousie University, Canada
A. Gölzhäuser, Universität Heidelberg, Germany
M. Grunze, Universität Heidelberg, Germany
Correspondent: Click to Email
Low Energy Electron Point Source Microscopy (LEEPS)@footnote 1,2@ has been used for taking in-line holograms of single DNA strands and carbon nanotubes. These two molecules were chosen to elucidate the extend to which the hologram images are determined by structural and electronic properties of the sample. The holograms were analyzed by reconstruction via the Kirchhoff-Helmholtz integral transformation.@footnote 3@ The resulting image is suggested to represent the scattering centers of the molecule, i.e. yielding its atomic structure. However, various effects can impose a limit to the resolution: vibrations between tip and sample, electronic charge deposition on the sample, non-ideal electron coherence, distortion of the electrical field near the sample molecule. It is discussed to which extend such artefacts are visible in the experimental data and whether they constrain the applicability of the Kirchhoff-Helmholtz transform. A comparison between the transformed images of DNA strands and carbon nanotubes shows differences that can be explained by properties of the molecules. @FootnoteText@ @footnote 1@ H.-W. Fink, W. Stocker and H. Schmid, Phys. Rev. Lett. 65, 1204 (1990). @footnote 2@ A. Gölzhäuser, B. Völkel, B. Jäger, M. Zharnikov, H.J. Kreuzer, M. Grunze, J. Vac. Sci. Technol. A16(5), 3025 (1998). @footnote 3@ H. J. Kreuzer, K. Nakumura, A. Wiezbicki, H.-W. Fink, and H. Schmid, Ultramicroscopy 45, 381 (1992).