Dresden 2011 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 59: Poster Session III (Nanotribology; Polymeric biomolecular films; Organic electronics and photovoltaics, Covalent networks on surfaces; Phase transitions; Particles and clusters; Transparent conductive oxides)

O 59.3: Poster

Mittwoch, 16. März 2011, 17:30–21:00, P3

Simulations of friction force microscopy on KBr(001) based on ab-initio forces — •Christine Wieferink, Peter Krüger, and Johannes Pollmann — Institut für Festkörpertheorie, WWU Münster

We report on ab-initio based simulations of friction force microscopy on the KBr(001) surface at zero and nonzero temperature. To simulate sliding friction we employ an extended three-dimensional Prandtl-Tomlinson model. The microscopic part of the tip is modeled by K⁺ and Br⁻ terminated tips. We use a tip-surface interaction potential, which is calculated within the local-density approximation of density-functional theory and supplemented by long-range van der Waals interaction resulting from the macroscopic part of the tip. The loading force acting on the tip enters the equation of motion separately from all other forces so that it can be changed at will. We find smaller sliding friction for the K⁺ compared to the Br⁻ tip. Especially we observe a very low sliding friction for the K⁺ tip at loading forces up to 1.5 nN.