Berlin 2012 – scientific programme

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O: Fachverband Oberflächenphysik

O 34: Poster Session I (Graphene; Plasmonics and nanooptics; Coherence and coherent control in nanophotonics and plasmonics)

O 34.4: Poster

Tuesday, March 27, 2012, 18:15–21:45, Poster E

Graphene on mica: corrugation of monolayer and stacking faults within few-layer graphene studied by scanning tunneling microscopy (STM) — •Silke Hattendorf, Alexander Georgi, Viktor Geringer, Marcus Liebmann, and Markus Morgenstern — II. Institute of Physics B and JARA-FIT, RWTH-Aachen

Graphene flakes were prepared on freshly cleaved mica by exfoliation. The topography of mono- and few-layer flakes was studied down to atomic resolution revealing an overall roughness of (61±13) pm on the monolayer, which is a bit more than measured recently with atomic force microscopy (24,1 pm) [2] but flat compared to graphene on silicon dioxide (320 pm) [1]. The corrugations are analyzed in respect to height and correlation length. The latter is determined by analyzing the auto correlation functions. The results are compared to those on silicon dioxide [1] and earlier measurements on a few-layer flake on mica.

On few-layer graphene on mica a large triangular network of partial dislocations separating differently stacked graphene areas was studied. Such networks have been observed before on HOPG [3,4]. Due to differences in the electronic structure of hexagonal and rhombohedral graphite, the differently stacked areas appear to be separated by edges of 1-4 Å height. This apparent height depends on the bias voltage. This dependency is studied by scanning tunneling spectroscopy (STS).

[1] V. Geringer et. al., Phys. Rev. Lett.102, 76102 (2009).

[2] C. Lui et. al., Nature 462, 339 (2009).

[3] S. Amelinckx and P. Delavignette, J. Appl. Phys. 31, 2126 (1960).

[4] S. Snyder et. al., Phys. Rev. B 47, 10823 (1993).