1. Sorbonne Universités, UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005, Paris, France
2. Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Dist., 100000 Hanoi, Vietnam
3. Laboratoire de Physique et d’Etude des Matériaux, ESPCI, UPMC Univ Paris 6, CNRS, 10 rue Vauquelin, Paris, France