1. Helmholtz Institute Ulm; 89081 Ulm Germany
2. Institute of Nanotechnology; Karlsruhe Institute of Technology; P.O. Box 3640 76021 Karlsruhe Germany
3. Institute for Applied Materials; Karlsruhe Institute of Technology; P.O. Box 3640 76021 Karlsruhe Germany
4. Technomedicum; Tallinn University of Technology; 19086 Tallinn Estonia
5. Joint Research Laboratory Nanomaterials; Technische Universität Darmstadt; 64287 Darmstadt Germany