1. Faculty of Physics, “Al. I. Cuza” University of Iasi, Iasi 700506, Romania
2. National Institute of Research and Development for Technical Physics, Iasi 700050, Romania
3. CNRS, Univ Paris 06, UMR 7070, LM2N, bât. F, B.P. 52, 4 place Jussieu, Paris F-75231 Cedex 05, France
4. Inst. für Struktur & Funktionskeramik, Montanuniversitaet Leoben, P. Tunner Straße 5, 8700 Leoben, Austria
5. RAMTECH Centre, “Al. I. Cuza” University of Iasi, Iasi 700506, Romania
6. ISTEC-CNR, Via Granarolo no. 64, I-48018 Faenza, Italy