1. Department of Chemistry, University of Zürich, CH-8057 Zürich, Switzerland
2. Department of Physics, University of Zürich, CH-8057 Zürich, Switzerland
3. Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
4. Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Joining Technologies and Corrosion, CH-8600 Dübendorf, Switzerland