1. Materials Research Department, GSI Helmholtz Centre for Heavy Ion Research, Planckstraße 1, 64291 Darmstadt, Germany
2. Material- und Geowissenschaften, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt, Germany
3. Stuttgart Centre for Electron Microscopy, MPI for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany