1. Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Rare Earth Materials Chemistry and Applications, College of Chemistry
and Molecular Engineering, Peking University, Beijing 100871, P. R. China
2. Ninhai Doubly Advanced Material Company, Ltd., Ninhai, 315602, China
3. Department
of Chemistry, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
4. Institute
of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, P. R. China
5. Department
of Engineering Science, Osaka Electro-Communication University, Osaka, 572-8530, Japan
6. Department
of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States