1. Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
2. CAS Center for Excellence in Nanoscience, Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology & University of Chinese Academy of Sciences, Beijing 100190, China
3. School of Physical Sciences and Technology, Electron Microscopy Centre of Lanzhou University, Lab of Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
4. College of Physics, Qingdao University, Qingdao 266000, China
5. Suzhou HWN Nanotec. Co., LTD., Suzhou 215123, China