1. MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Key Laboratory of Optical and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
2. College of Science, Guilin University of Technology, Guilin 541004, P. R. China
3. Spallation Neutron Source Science Center, Dongguan 523803, P. R. China
4. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China
5. Songshan Lake Materials Laboratory, Dongguan 523808, P. R. China
6. College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, P. R. China