1. Institute for Nanotechnology; Karlsruhe Institute of Technology (KIT); Hermann-von-Helmholtz Platz 1 76344 Eggenstein-Leopoldshafen Germany
2. KIT-TUD Joint Research Laboratory Nanomaterials; Technische Universität Darmstadt (TUD); Institute of Materials Science; Jovanka-Bontschits-Str. 2 64287 Darmstadt Germany
3. Karlsruhe Nano Micro Facility; Karlsruhe Institute of Technology (KIT); Hermann-von-Helmholtz Platz 1 76344 Eggenstein-Leopoldshafen Germany
4. Department of Materials Engineering; Indian Institute of Science; Bangalore 560012 India