1. Department of Physics
2. Faculty of Science
3. University of Oviedo
4. 33007 Oviedo
5. Spain
6. Evonik Technology and Infrastructure GmbH
7. Germany
8. Leibniz Institute for Solid State and Materials Research (IFW) Dresden
9. 01069 Dresden
10. Bundesanstalt für Materialforschung und -prüfung (BAM)
11. Berlin