Berlin 2012 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 58: Poster Session III (Solid/liquid interfaces; Metals; Semiconductors; Oxides and insulators)
O 58.43: Poster
Mittwoch, 28. März 2012, 18:15–21:45, Poster B
Ultrathin samaria films on Pt(111) studied by PES and LEED — •J.H. Jhang1, A. Schaefer1, D. Ragazzon2, L.E. Walle3, M.H. Farstad3, A. Borg3, A. Sandell2, and M. Bäumer1 — 1Institute for Applied and Physical Chemistry, Universität Bremen, Germany — 2Department of Physics and Astronomy, Uppsala University, Sweden — 3Department of Physics, NTNU, Trondheim, Norway
Rare earth oxides (REOs) exhibit high potential as catalysts due to the ability to easily switch between oxidation states. Their catalytic capability depends strongly on the storage and release of oxygen. The tendency to promote partial or total oxidation reactions is influenced by the existing oxidation states and oxygen mobility: While ceria (3+ and 4+ as stable oxidation states) is a good catalyst for total oxidation, samaria (only 3+ as stable oxidation state) seems to be the most effective REO for partial oxidation of methane, to just name one example. Therefore, in order to look into the atomic details of oxygen transport and transfer a simplified two dimensional model system may be prepared and studied under controlled conditions in ltra-high vacuum (UHV). Studies of REO films other than ceria are however very limited. This makes the exploration of other REOs highly motivated. We present first results on samaria growth on Pt(111) by using physical vapour deposition (PVD) in UHV. Two methods will be presented for samaria growth: oxidation of a surface alloy and deposition in elevated oxygen background pressure. The generated oxide layers are investigated by synchrotron radiation based photoelectron spectroscopy (PES) and low energy electron diffraction (LEED).