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O: Fachverband Oberflächenphysik
O 56: Metal substrates: Epitaxy, growth and adsorbates
O 56.5: Talk
Thursday, March 26, 2009, 16:00–16:15, SCH A316
Growth of ultra-thin Ag films on Ni(111) — •Axel Meyer1, Jan Ingo Flege1, Sanjaya Senanayake2, Faisal Alamgir3, and Jens Falta1 — 1Institute of Solid State Physics, University of Bremen, 28359 Bremen, Germany — 2Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA — 3Georgia Institute of Technology, Atlanta, GA 30332-0245, USA
The physical and chemical properties of ultra-thin metal films on metallic substrates strongly depend on their morphology and the structure of the buried interface. Hence, detailed knowledge of the growth mechanisms is essential for the creation of new functional materials with novel characteristics. In this contribution, we present a comprehensive structural study of the growth and properties of epitaxial Ag films on Ni(111) by in-situ low energy electron microscopy (LEEM).
For lower temperatures, the growth of the Ag film proceeds in a Stranski-Krastanov mode after completion of the wetting layer, while for higher temperatures layer-by-layer growth is observed. Quantitative information about the film structure were obtained by analyzing the intensity-voltage (I-V) dependence of the local electron reflectivity (IV-LEEM). The corresponding I(V) spectra showed intensity oscillations depending on local thickness of the Ag film due to the quantum size effect (QSE). Modeling of the I(V) spectra was performed both within the framework of a one-dimensional Kronig-Penney model and multiple scattering IV-LEED calculations. The results of both approaches concerning the variation of the layer spacings and interface characteristics for different temperatures and film thicknesses will be discussed.