1. Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
2. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
3. State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China
4. Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
5. Institute of Functional Crystal Materials, Tianjin University of Technology, Tianjin 300384, P. R. China