1Research Center of Materials Science, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081 P.R. China
2Department of Physics, Beihang University, Beijing, 100191, P. R. China.
3Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 P.R. China
4Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Shanghai, 201800 P.R. China
5Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, P. R. China
6Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW, 2500, Australia
