1. Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education
2. School of Physical Science and Technology and Electron Microscopy Centre of Lanzhou University
3. Lanzhou University
4. Lanzhou 730000
5. P. R. China
6. Key Laboratory of Magnetic Materials and Devices
7. Ningbo Institute of Material Technology and Engineering
8. Chinese Academy of Sciences
9. Ningbo 315201
10. Division of Physical Science and Engineering
11. King Abdullah University of Science and Technology (KAUST)
12. Thuwal 239955
13. Kingdom of Saudi Arabia