Regensburg 2007 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 17: Poster Session I (Nanostructures at Surfaces; Metal Substrates: Epitaxy and Growth; Methods: Scanning Probe Techniques; Phase Transitions)
O 17.81: Poster
Montag, 26. März 2007, 17:30–20:30, Poster C
Heteroepitaxial Praseodymium sesquioxide films on Si(111): A future model catalyst system for praseodymium oxide based catalysts — •Andreas Schaefer1, Thomas Schröder2, Gregorz Lupina2, Yulia Borchert1, Jarek Dabrowski2, Christian Wenger2, and Marcus Bäumer1 — 1Universität Bremen, Institut für Angewandte und Physikalische Chemie, Leobener Str. 2, 28359 Bremen — 2IHP-Microelectronics, Im Technologiepark 25, 15236 Frankfurt (Oder)
Rare Earth Oxides (REO) are promising candidates for applications in catalysis based on their high oxygen storage capability and oxygen mobility. In order to look into the atomic details of oxygen transport and transfer of such materials interacting with adsorbed molecules, a simplified two dimensional model system of the generally three dimensional catalyst may be prepared and studied under controlled conditions in an UHV environment. The structure, growth and stoichiometry of heteroepitaxial Pr2O3 films on Si(111) were characterized by a combined RHEED, XRD, XPS and UPS study as a prerequisite for any future model catalytic investigations. RHEED and XRD confirm the growth of a (0001) oriented hexagonal Pr2O3 phase on Si(111). After an initial nucleation stage RHEED growth oscillation studies point to a Frank-van der Merwe growth mode up to a thickness of approximately 12 nm. XPS and UPS prove that the initial growth of the Pr2O3 layer on Si up to 1 nm thickness is characterized by an interface reaction with Si. Nevertheless stoichiometric Pr2O3 films of high crystalline quality form on top of these Pr-silicate containing interlayers.