Regensburg 2004 – wissenschaftliches Programm

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O: Oberflächenphysik

O 39: Epitaxie und Wachstum III

O 39.6: Vortrag

Donnerstag, 11. März 2004, 17:00–17:15, H39

Kinetic lattice Monte-Carlo simulations of stacking fault nucleation on Ir(111) — •Michael Müller and Karsten Albe — TU Darmstadt, FB Materialwissenschaft, Petersenstraße 23, 64289 Darmstadt

A prominent fault during epitaxial growth of face-centered-cubic (111) metal surfaces is the formation of adatom islands that nucleate and grow in the hexagonal-close-packed stacking. For sub-monolyer growth on Ir(111) detailed experimental data on the temperature dependence of the probability of stacking fault island formation is available from scanning tunneling microscopy. Here, we present kinetic lattice Monte-Carlo (KLMC) simulations of homoepitaxial island growth on Ir(111) that are able to reproduce the experimentally observed shape and distribution of stacking fault islands over a wide temperature range. In our simulations, atomic positions are not restricted to perfect fcc lattice sites, as it is the case in conventional KLMC. Therefore, an effective method to implement a refined lattice that includes fcc as well as hcp sites is presented. Also, the diffusion behavior of small adatom clusters plays a central role for the formation of stacking fault islands on Ir(111). Our KLMC simulations identify adatom clusters on the surface. In addition to single adatoms, these clusters are also treated as mobile species.