1. School of Materials Science and Engineering
2. Beihang University
3. Beijing 100191
4. P. R. China
5. Wuhan National High Magnetic Field Center
6. Huazhong University of Science and Technology
7. Wuhan 430074
8. College of Materials Science and Engineering
9. Key laboratory of Advanced Functional Materials
10. Ministry of Education of China
11. Beijing University of Technology
12. Beijing 100124
13. School of Physics