[1] Chinese Acad Sci, Inst Coal Chem, State Key Lab Coal Convers, Taiyuan 030001, Peoples R China
[2] Max Planck Inst Microstruct Phys, D-06120 Halle, Germany
[3] Ecole Polytech, Dept Engn Phys, Montreal, PQ H3C 3A7, Canada
[4] Ikerbasque, Basque Fdn Sci, Bilbao 48011, Spain
[5] CIC nanoGUNE Consolider, Donostia San Sebastian 20018, Spain