Berlin 2005 – wissenschaftliches Programm

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O: Oberflächenphysik

O 32: Nanostrukturen III

O 32.4: Vortrag

Montag, 7. März 2005, 11:30–11:45, TU EB202

Tip-substrate interaction at the atomic scale — •A.L. Klavsyuk, V.S. Stepanyuk, R.Z. Huang, P. Bruno, and J. Kirschner — Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany

Performing atomic-scale simulations with ab initio based many-body potentials we demonstrate that the concept of size-dependent mesoscopic relaxations introduced for homo-and heteroepitaxy[1] should be used to describe the interaction of the STM tip with adatoms, nanoislands and steps at the atomic scale. We concentrate on Co adatoms, islands on Cu(001), and embedded Co atoms in Cu(100). Strongly inhomogeneous deformations of the substrate and islands are revealed when the tip approaches the surface. The shape of islands, tip and the substrate is found to strongly depend on the island size and the tip-island distance. We show that atomistic processes in the early stages of growth, such as the diffusion of an adatom on a flat surface and on top of islands, are strongly influenced by the tip. The possibility of controlling the dynamics of single adatoms exploiting the tip-substrate interaction is discussed. We reveal an essential role of the mesoscopic stress induced by the tip on a controlled movement of single atoms of Co incorporated in the surface.

[1] O.V. Lysenko, V.S. Stepanyuk, W. Hergert, and J. Kirschner, Phys. Rev.Lett. 89, 126102 (2002)