Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 41: Poster Session I (Semiconductor Substrates: Epitaxy and growth; Semiconductor Substrates: Adsorbtion; Semiconductor Substrates: Solid-liquid interfaces; Semiconductor Substrates: Clean surfaces; Oxides and insulators: Epitaxy and growth; Oxides and insulators: Adsorption; Oxides and insulators: Clean surfaces; Organic, polymeric and biomolecular films - also with adsorbates; Organic electronics and photovoltaics, Surface chemical reactions; Heterogeneous catalysis; Phase transitions; Particles and clusters; Surface dynamics; Surface or interface magnetism; Electron and spin dynamics; Spin-Orbit Interaction at Surfaces; Electronic structure; Nanotribology; Solid/liquid interfaces; Graphene; Others)
O 41.100: Poster
Dienstag, 23. März 2010, 18:30–21:00, Poster B1
Ab initio based simulations of atomic force and friction force microscopy of KBr(001) — •Christine Broelemann, Peter Krüger, and Johannes Pollmann — Institut für Festkörpertheorie, Universität Münster
Atomic force microscopy offers the capability to investigate surface structure with atomic resolution. In addition, it allows one to study frictional phenomena of single contacts. To analyse the information that can be extracted from such experimental studies theoretical explorations are essential.
We report on ab initio based simulations of noncontact AFM images, corresponding force fields and friction force line profiles. The short range part of the tip-sample interaction potential is calculated within the local-density approximation of density-functional theory and is supplemented by the long range van-der-Waals interaction due to the macroscopic part of the tip. The microscopic part is modeled by K+ and Br− terminated tips.
We use an extended Tomlinson model employing the van-der-Waals interaction together with the DFT derived interaction potential to simulate the sliding friction on the surface. Solving the equations of motion within this framework, we obtain lateral force line profiles with typical stick-slip characteristics. The dependance of the results on different tip types as well as on the spring constant and loading force is discussed.