Dresden 2003 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 36: Hauptvortrag Bennewitz

O 36.1: Hauptvortrag

Freitag, 28. März 2003, 10:15–11:00, HSZ/02

Local atomic structure of surfaces of insulators — •Roland Bennewitz — Institut für Physik, Universität Basel, Klingelbergstr. 82, CH-4056 Basel

Low-coordinated sites play a crucial role in many processes at surfaces of insulators, like thin film growth, nucleation of adsorbates, or preferential desorption. High-resolution force microscopy allows to image these sites, as we will demonstrate on the examples of ultrathin films of NaCl, molecular adsorption at steps on KBr, and nanoscale pits in KBr produced by electron irradiation. Even chemical resolution of different ions in a mixed alkali halide has been obtained. Beyond pure imaging, force microscopy experiments reveal the enhanced interaction at low-coordinated sites. The capability of measuring forces at the intermolecular level becomes particularly interesting when the surface structure is manipulated by the action of the force microscope tip. For example, the onset of abrasive wear has been studied on the atomic scale. We will finally discuss a proposal how to measure lateral forces on surfaces in molecular manipulation experiments.