1. Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria
2. Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, S-581 83 Linköping, Sweden
3. Materials Center Leoben Forschung GmbH, Roseggerstrasse 12, A-8700 Leoben, Austria
4. Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, A-8010 Graz, Austria
5. Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Cyclotron Road 1, Berkeley, California 94720, USA