1. Faculty of Production Engineering University of Bremen Badgasteiner Straße 1 28359 Bremen Germany
2. Institute of Applied and Physical Chemistry and Center for Environmental Research (UFT) University of Bremen Leobener Straße 6 28359 Bremen Germany
3. Leibniz Institute for Materials Engineering IWT Badgasteiner Straße 3 28359 Bremen Germany
4. Institute of Solid State Physics University of Bremen Otto-Hahn-Allee 1 28359 Bremen Germany
5. MAPEX Center for Materials and Processes University of Bremen Postfach 330 440 Germany