1. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
2. Institut des Nanotechnologies de Lyon, CNRS UMR 5270, Ecole Centrale de Lyon, Université de Lyon, 69134 Ecully, France
3. IHP—Innovations for High Performance Microelectronics, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany
4. CEMES-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse, France