Dresden 2006 – wissenschaftliches Programm
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O: Oberflächenphysik
O 14: Poster session I (Adsorption, Epitaxy and growth, Phase transitions, Surface reactions, Organic films, Electronic structure, Methods) (sponsored by Omicron Nanotechnology GmbH)
O 14.78: Poster
Montag, 27. März 2006, 18:00–21:00, P2
Positron annihilation induced Auger electron spectroscopy at Au-layers on Cu and Si — •Jakob Mayer1, Christoph Hugenschmidt1,2, and Klaus Schreckenbach1,2 — 1Technische Universität München, Physikdepartment E21, James-Franck-Str., 85748 Garching — 2Technische Universität München, ZWE FRM-II, Lichtenbergstr. 1, 85748 Garching
At the new positron source NEPOMUC at the FRM-II in Munich a low-energy (15eV) positron beam with an intensity of 107-108 moderated positrons per second is available. This enables positron annihilation induced Auger electron spectroscopy (PAES) within a short measurement time (few hours/spectrum). Up to now qualitative PAES measurements of Au on Cu have been performed to show the feasibility of this technique.
At present, Au covered single crystals of Cu and Si are prepared in order to determine the sensitivity of this technique quantitatively. For this purpose, the thickness of the Au layer is even chosen in the sub-monolayer range (0.1 ML-10 ML). For the analysis of the spectra besides the layer thickness of the adsorbed material its positron affinity (A+) as well as the A+ of the substrates has to be taken into account. Therefore the systems Au/Si and Au/Cu were chosen, since the A+ of Si (A+,Si= -6,95) is similar to the A+ of Au (A+,Au= -6,30), whereas in the latter system the A+ of the Cu substrate is much larger (A+,Cu= -4,57) than A+,Au. The results of the measurements are always compared with conventional AES.