1. Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, 21502 Geesthacht, Germany
2. Institute of Materials Physics and Technology, Hamburg University of Technology, Eißendorferstr. 42, 21073 Hamburg, Germany
3. Institute of Advanced Ceramics, Hamburg University of Technology, Denickestr. 15, 21073 Hamburg, Germany