1. MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Key Laboratory of Optic and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
2. Spallat. Neutron Source Sci. Ctr, Dongguan 523803, P. R. China
3. Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, P. R. China
4. Songshan Lake Mat Lab, Dongguan 523808, P. R. China
5. College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, P. R. China