1. Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping, Sweden
2. Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
3. Rensselaer Polytechnic Institute, Department of Mechanical, Aerospace, and Nuclear Engineering, Troy, NY 12180, USA