Dresden 2009 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 42: Poster Session II (Nanostructures at surfaces: arrays; Nanostructures at surfaces: Dots, particles, clusters; Nanostructures at surfaces: Other; Nanostructures at surfaces: Wires, tubes; Metal substrates: Adsorption of O and/or H; Metal substrates: Clean surfaces; Metal substrates: Adsorption of organic/bio moledules; Metal substrates: Solid-liquid interfaces; Metal substrates: Adsorption of inorganic molecules; Metal substrates: Epitaxy and growth; Heterogeneous catalysis; Surface chemical reactions; Ab-initio approaches to excitations in condensed matter; Organic, polymeric, biomolecular films– also with adsorbates; Particles and clusters)
O 42.81: Poster
Mittwoch, 25. März 2009, 17:45–20:30, P2
Nucleation of Cu on Cu(001) by pulsed laser deposition — •Andreas Dobler and Thomas Fauster — Lehrstuhl für Festkörperphysik, Universität Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen
For submonolayer homoepitaxial growth, nucleation theory allows to extract the critical island size by scaling island densities with the deposition rate. Pulsed laser deposition provides instantaneous deposition rates up to 104 ML/s and particle energies up to hundreds of eV.
We measured island densities after pulsed laser deposition of Cu on Cu(001) at 300 K. For best focus conditions (I≈ 10 J/cm2), we varied the average deposition rate F from 10−5 to 10−2 ML/s at 1 Hz repetition rate. The saturation island density scales as nx ∝ Fp with an exponent near the value for thermal deposition of p = 0.4. However, the experimental island density is two orders of magnitude lower than expected by considering the instantaneous flux. This result is in good agreement with a theoretical study of nucleation for pulsed fluxes considering dimer mobility [1].
[1] N. Combe and P. Jensen, Phys. Rev. B 57 (1998) 15553