1. Department of Applied Physics, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel
2. Institut für Physik kondensierter Materie, Technische Universität Darmstadt, Hochschulstraße 6, 64289 Darmstadt, Germany
3. Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastian, Spain
4. The Hebrew University of Jerusalem, Racah Institute of Physics, Edmond J. Safra Campus, Jerusalem 9190401, Israel
5. Grebenshchikov Institute of Silicate Chemistry, Russian Academy of Sciences, Makarova emb., 2, Saint-Petersburg 199034, Russia
6. Centro de Física de Materiales (CFM CSIC/EHU) - Material Physics Centre (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastian, Spain