Regensburg 2004 – wissenschaftliches Programm
O 32.3: Vortrag
Donnerstag, 11. März 2004, 11:45–12:00, H38
Epitaxial growth of transition metals on the Ir (100) - (5 × 1) surface — •Chiara Giovanardi, Andreas Klein, Andreas Schmidt, Lutz Hammer, and Klaus Heinz — Lehrstuhl für Festkörperphysik, Universität Erlangen- Nürnberg, Staudtstr. 7, D-91058 Erlangen
The early growth stages of transition metals (Fe, Ni, Co) on the quasi-hexagonally reconstructed Ir(100)-(5×1) surface have been studied by Scanning Tunnelling Microscopy (STM) and quantitative Low Energy Electron Diffraction (LEED). The periodic corrugation of the reconstructed Ir surface rules the growth of the metal by promoting the diffusion of atoms within the one dimensional troughs of the surface layer. At sub-monolayer coverage, linear chains are therefore formed with their length increasing with increasing substrate temperature during deposition. Laterally, the chains are mostly diatomic, but for Ni and Co also triple and quadruple chains are observed. Recently published DFT calculations  claim that Fe atoms reside in short bridge sites, while our experimentally based LEED analisys favours the long bridge position, as directly imaged by STM in the case of Ni chains, too. With increasing coverage, the hexagonal reconstruction is locally lifted. This is prior to the chain phase covering the whole surface and a surface compound (e. g. Fe4Ir ) forms.
 D. Spišák and J. Hafner, Surf. Sci. 546 (2003) 47