Berlin 2015 – scientific programme

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O: Fachverband Oberflächenphysik

O 79: Scanning Probe Techniques: STM

O 79.8: Talk

Thursday, March 19, 2015, 12:30–12:45, HE 101

Role of the microscopic tip apex in STM-IETS measurements — Norio Okabayashi^{1, 2}, Alexander Gustafsson³, •Angelo Peronio¹, Magnus Paulsson³, Toyoko Arai², and Franz J. Giessibl¹ — ¹Institute of Experimental and Applied Physics, University of Regensburg, D-93053 Regensburg, Germany — ²Graduate School of Natural Science and Technology, Kanazawa University, Ishikawa, Japan — ³School of Computer Science, Physics and Mathematics, Linnaeus University, 391 82 Kalmar, Sweden

The tunnelling process at the heart of Scanning Tunnelling Microscopy (STM) involves both the electronic states of the sample under study and of the tip of the microscope. Hence, STM imaging and spectroscopy are heavily affected by the microscopic structure of the tip apex, which is difficult to characterize. This uncertainty can be in addressed by combined STM/AFM experiments, using an adsorbed CO molecule to image the tip apex itself, the so-called COFI technique [1].

With this technique, we addressed the role of tip apex termination in IETS vibrational spectroscopy, by investigating single CO molecules adsorbed on a copper surface.

References:

[1] Hofmann T, Pielmeier F, and Giessibl FJ. Chemical and Crystallographic Characterization of the Tip Apex in Scanning Probe Microscopy. Physical Review Letters 112 066101 (2014). http://dx.doi.org/10.1103/PhysRevLett.112.066101