Regensburg 2004 – wissenschaftliches Programm

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O: Oberflächenphysik

O 5: Epitaxie und Wachstum I

O 5.2: Vortrag

Montag, 8. März 2004, 11:30–11:45, H44

Nucleation in the presence of adatom insertion: Co/Pt(111) — •Philipp Buluschek, Stefano Rusponi, Mehdi El Ouali, Emmanuel Vargoz, Klaus Kern, and Harald Brune — Institut de Physique des Nanostructures, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland

We used variable temperature STM to study submonolayer nucleation of Co/Pt(111). The Pt(111) surface is under tensile stress and undergoes a reconstruction above 1330 K, or upon Pt deposition at 400 K. For Co deposition, adatom incorporation into the first atomic plane has been reported upon deposition at 300 K. We show that conventional on-surface diffusion and nucleation takes place up to 180 K. Above this temperature the island density continues to decrease but with a smaller slope in its Arrhenius representation. Our experiments demonstrate that this coincides with the onset of inclusion.

We present kinetic Monte-Carlo simulations revealing that insertion leads to the creation of repulsive point and line defects. The comparison between simulations and experiment enables access to the energy barriers for surface diffusion, insertion and the repulsion at the defects.