1. State Key Laboratory for Physical Chemistry of Solid Surfaces, and Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen University Xiamen 361005 P. R. China
2. Xiamen Institute of Rare Earth MaterialsHaixi institutesChinese Academy of Sciences Xiamen 361021 P. R. China
3. National High Magnetic Field Laboratory 1800 E. Paul Dirac Drive Tallahassee FL 32310 USA
4. School of Energy ResearchXiamen University Xiamen 361005 P. R. China