1. Department of Informatics and Microsystem Technology; University of Applied Sciences Kaiserslautern; Amerikastr. 1 66482 Zweibrücken Germany
2. RAM Group DE GmbH; Research Development Center; Amerikastr. 15 66482 Zweibrücken Germany
3. Department of Physics; RWTH Aachen University; Sommerfeldstr. 14 52074 Aachen Germany
4. Department of Physics and Astronomy; Catholic University Leuven; Celestijnenlaan 200d 3001 Leuven Belgium
5. Institute for Materials Research; Hasselt University; Agoralaan Building D 3590 Diepenbeek Belgium