1. Christian Doppler Laboratory for Direct-Write Fabrication of 3D Nano-Probes, Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, 8010 Graz, Austria
2. Graz Centre for Electron Microscopy, 8010 Graz, Austria
3. Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, 8010 Graz, Austria