1. State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
2. Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, China.
3. Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA.
4. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
5. Foshan (Southern China) Institute for New Materials, Foshan, China.
6. The Future Laboratory, Tsinghua University, Beijing, China.
7. National Center of Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.