Berlin 2005 – wissenschaftliches Programm
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O: Oberflächenphysik
O 32: Nanostrukturen III
O 32.5: Vortrag
Montag, 7. März 2005, 11:45–12:00, TU EB202
STM characterisation and tip-induced nanostructuring of surface-frozen interfaces in a Ga-Bi alloy — •Andrey Turchanin1,2, Alexander Issanin1, and Werner Freyland1 — 1Institut für Physikalische Chemie, Universität Karlsruhe (TH), Kaiserstr. 12, D-76128 Karlsruhe — 2Fakultät für Physik, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld
We report results of a UHV-STM study of the Bi solid/vapour interface in a solidified Ga-Bi alloy after passing a surface freezing transition. The topology at room temperature is characterized by extended monoatomic Bi terraces with dimensions up to several micrometers. We show for the first time that the application of negative/positive pulses of the bias voltage in the constant current mode results in modification of the Bi interface in the nanometer regime. Particularly unusual is the observation, that deposition and withdraw of Bi is possible by changing the pulse polarity. In this way different nanostructures (cavities, grooves, islands, lines etc.) can be produced. They show unusually high thermal stability at room temperature. For instance, monoatonic cavities with a diameter of 6 nm persist at the surface for at least three weeks. To rationalize the nanostructuring mechanisms different parameters have been studied including the threshold values of the applied pulses and their dynamics. An analysis of these different parameters will be given.