Regensburg 2013 – scientific programme
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O: Fachverband Oberflächenphysik
O 58: Poster Session III (Solid-liquid interfaces; Scanning probe and other methods; Electronic structure theory; Spin-orbit interaction)
O 58.38: Poster
Wednesday, March 13, 2013, 18:15–21:45, Poster B1
FIM meets AFM: Quantification of Long-Range Forces in Non-Contact Atomic Force Spectroscopy using Field Ion Microscopy Characterized Tips — •Jens Falter1,2, Gernot Langewisch2, Hendrik Hölscher3, Harald Fuchs2, and André Schirmeisen1 — 1Institute of Applied Physics (IAP), Justus-Liebig-University Giessen — 2Center for Nanotechnology (CeNTech) and Institute of Physics, University of Muenster (WWU) — 3Karlsruhe Institute of Technology (KIT), Karlsruhe
Non-contact Atomic Force Microscopy (ncAFM) is capable to measure interaction forces between the probing tip and the sample with atomic precision. Although the sample can be imaged with atomic resolution, the structure of the tip remains unknown in most ncAFM experiments. Therefore, a quantitative comparison to models from theory is often impossible. Here we present long range ncAFM force spectroscopy experiments with FIM characterized tungsten tips on Ag(111) [1]. With the additional information about the tip geometry, the measured forces can be compared to analytical models. Our analysis shows a quantitative agreement between experiment and theory for the van der Waals- and electrostatic forces [2, 3]. Even more interestingly our approach provides a value for the absolute tip sample distance. Furthermore, an additional force contribution of long range character can be separated and assigned to arise from so called "patch charges" [4].
[1] J. Falter et al, submitted to PRB (2012) [2] S. Hudlet et al, Eur. Phys. J. B 2, 5-10 (1998) [3] C. Argento and R.H. French, J. Appl. Phys. 80 (11), (1996) [4] N.A. Burnham, Phys. Rev. Lett. 69, 1 (1992)