Regensburg 2007 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 20: POSTER: Biological Systems + New Materials

CPP 20.32: Poster

Wednesday, March 28, 2007, 16:00–18:30, Poster B

Simultaneous scanning tunneling and atomic force microscopy at ambient conditions using quartz tuning fork sensors — •Stefan Strömsdörfer, Viatcheslav Dremov, Irina Lazareva, Yuri Koval, and Paul Müller — Physikalisches Institut 3, Universität Erlangen-Nürnberg, Germany

We demonstrate the operation of a tuning fork based AFM in non-contact mode with simultaneous acquisition of both the tunneling current and the frequency shift of a vibrating conducting cantilever.

We were able to show atomic resolution of the graphite lattice of HOPG at ambient conditions. Whereas STM shows the well known mapping of every second carbon atom, in AFM the complementary subset of carbon atoms was visualized. These results agree qualitatively with previous measurements performed in UHV.

As the frequency shift, i.e. the force gradient determines the control, there is no restriction on the conductivity of the samples. The technique enables measurements of the tunneling current even if the sample surface contains insulating regions. We applied this method in the measurement of the conductivity along nanowires deposited onto an insulating substrate.