Regensburg 2010 – scientific programme
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O: Fachverband Oberflächenphysik
O 57: Surface dynamics II
O 57.6: Talk
Wednesday, March 24, 2010, 16:15–16:30, H40
Investigation of thin Cu films on Fe/Pd and their dynamics with Positron annihilation induced Auger electron spectroscopy — •Jakob Mayer1,2, Klaus Schreckenbach1,2, and Christoph Hugenschmidt1,2 — 1TU München, Lehrstuhl E21, James-Franck Straße, 85748 Garching — 2ZWE FRM-II, Lichtenbergstr. 1, 85747 Garching
Positron annihilation induced Auger Electron Spectroscopy (PAES) is a powerful technique to investigate the topmost atomic layer of a sample. This is due to the different hole creation process by positron electron annihilation and due to the trapping of the positron at the surface of the sample. With conventional positron beam setups the measurement time for one PAES-spectrum amounted to several days. Now, with the highly intense positron beam NEPOMUC at the FRM-II in Munich (9· 108 e+/s), it is possible to record a PAES spectrum within less than one hour. For the first time we succeeded to observe dynamic processes at the surface with PAES. Measurements of thin Cu layers (0.3-4ML) on Fe and Pd samples will be presented and the higher surface selectivity of PAES compared to conventional EAES will be shown. Furthermore, diffusion of Cu into the bulk of Pd was observed.