1. Beijing Center for Crystal R&D
2. Key Lab of Functional Crystals and Laser Technology
3. Technical Institute of Physics and Chemistry (TIPC)
4. Chinese Academy of Sciences (CAS)
5. Beijing 100190, PR China
6. Key Laboratory of Cryogenics
7. TIPC
8. CAS
9. Beijing, PR China
10. Department of Materials Science and Metallurgy
11. University of Cambridge
12. Cambridge CB3 0FS, UK