1. SPCTS, UMR 7315,
ENSCI, CNRS; Centre Européen de la Céramique, 12 rue Atlantis, 87068 Limoges cedex, France
2. Institut
des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP32229, 44322 Nantes cedex 3, France
3. Department
of Applied Physics and COMP CoE, Aalto University School of Science, P.O. Box 11000, FI-00076 Aalto, Espoo, Finland
4. Department
of Physics, Brown University, Providence, Rhode Island 02912-8143, United States
5. Dipartimento
di
Fisica and CNR-IMEM, Via Dodecaneso
33, Genova I-16146, Italy