Regensburg 2004 – wissenschaftliches Programm

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O: Oberflächenphysik

O 14: Postersitzung (Adsorption an Oberflächen, Epitaxie und Wachstum, Organische Dünnschichten, Oxide und Isolatoren, Phasenübergänge, Rastersondentechniken, Struktur und Dynamik reiner Oberflächen)

O 14.28: Poster

Montag, 8. März 2004, 18:00–21:00, Bereich C

Rate equation approach to stacking-fault nucleation in epitaxial growth — •Celia Polop, Carsten Busse, Andreas Gödecke, and Thomas Michely — I. Physikalisches Institut, RWTH Aachen, 52056 Aachen

One of the most important defects for thin film growth is the stacking-fault. Growth in the presence of stacking-faults leads to twin crystallite formation and incoherent twin boundaries. Therefore the density of stacking-faults is decisive for the film quality.

Here, we present an atomistic model for the nucleation of stacking-fault islands on dense packed surfaces based on rate equations. Mean-field rate equations taking into account two kinds of adsorption sites (fcc and hcp) are able to reproduce the temperature and flux dependence of the formation probability of stacking-fault islands on Ir(111) as determined by our STM experiments [1]. The rate analysis of the atomistic processes that take place during growth provides a kinetic model for the stacking-fault island formation: for a given temperature, the distribution of large and metastable stacking-fault islands is governed by the equilibrium distribution of the largest mobile cluster.

[1] C. Busse, C. Polop, M. Müller, K. Albe, U. Linke, T. Michely, Phys. Rev. Lett. 91, 56103-1/4 (2003).