Dresden 2006 – wissenschaftliches Programm
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DS: Dünne Schichten
DS 23: Nanowires, nanoparticles and nanostructures
DS 23.6: Vortrag
Donnerstag, 30. März 2006, 17:15–17:30, GER 38
Large-scale fabrication of Au nanostructures in the process of amalgam formation followed by Au-Hg alloy thermal decomposition — •Tomasz Kobiela — University of Bonn, Institute of Physical and Theoretical Chemistry, Wegelerstrasse 12, D-53115 Bonn, Germany — Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
Formation of gold nanostructures onto surfaces is fundamental process for fabricating various micro/nano devices and systems. These nanostructures exhibit not only the novel physical properties, but are commercially used in the electronic devices, catalysts and efficient biomolecular sensors. In this work, Au films deposited under ultra-high vacuum conditions on air-cleaved mica substrates were exposed "in situ" to Hg vapor (residual gas pressure 1x10−7 Pa, with Hg vapor pressure 0.24 Pa). This led to transformation of continuous gold film into isolated amalgam islands of nanometer scale. The changes of Au thin film surface topography caused by amalgamation carried out within 40 h was studied by the atomic force microscopy method, while the phase transition in the bulk of Hg-dosed Au films was monitored by means of X-ray diffraction. The islands’ morphology varies from irregular, ramified structures on terraces to compact shapes along the steps on the mica substrate. After thermal decomposition of the amalgam, thin gold films consisting of isolated Au nanostructures on mica can be obtained. The experimental data are compared with theoretical calculations of the kinetic processes occurring at the thin Au film surface.