1. School of Materials Science and Engineering, Research Center of Rare Earth and Inorganic Functional Materials, State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin 300350, China
2. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China
3. University of Chinese Academy of Sciences, Beijing 100049, P. R. China