Regensburg 2007 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 44: Poster Session II (Semiconductors; Oxides and Insulators: Adsorption, Clean Surfaces, Epitaxy and Growth; Surface Chemical Reactions and Heterogeneous Catalysis; Surface or Interface Magnetism; Solid-Liquid Interfaces; Organic, Polymeric, Biomolecular Films; Particles and Clusters; Methods: Atomic and Electronic Structure; Time-resolved Spectroscopies)

O 44.35: Poster

Mittwoch, 28. März 2007, 17:00–19:30, Poster C

Fabrication and Characterization of Gold Nanocrystals on NaCl(001)-Surfaces — •Andreas Winter, Jawad Slieh, Armin Brechling, Wiebke Hachmann, Ulf Kleineberg, and Ulrich Heinzmann — University of Bielefeld, Faculty of Physics, D-33615 Bielefeld

We report on the fabrication of dispersive gold nanocrystals using a vacuum evaporation technique. Gold has been evaporated under ultra high vacuum conditions on a freshly cleaved NaCl(001) surface. The substrate temperature, the averaged thickness and the potential of the sample were studied systematically. After preparation, the gold nanocrystals have been characterized by means of different techniques such as Atomic Force Microscopy (AFM), Transmissions Electron Microscopy (TEM), X-Ray Diffraction (XRD) and Laue Diffraction. Depending on the preparation parameters, the gold grows in clusters with lateral and vertical sizes between 10 nm and 25 nm. XRD-measurements revealed a crystal growth with a preferred orientation of the Au(001)-axis parallel to the NaCl(001)-axis. A second Au(111) orientation, parallel to the NaCl surface normal was observed at a substrate potential between 200 V and 400 V and a substrate temperature of ca. 300^∘C, only. Estimations of the cluster size, measured by AFM, and the crystal size, measured by XRD exhibit comparable results, which indicate a high amount of single gold crystals. TEM-images, made after dissolving the gold-crystals in an aqueous CHAPS-solution support these results.