1. Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
2. Technische Universität Chemnitz, Chemnitz 09126, Germany
3. EMPA-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
4. Fraunhofer Institute for Electronic Nano Systems, Chemnitz 09126, Germany
5. Institute of Solid State Physics, TU Dresden, Dresden 01069, Germany
6. Helmholtz-Zentrum Berlin für Materialen und Energie, Berlin 12489, Germany