1. CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315201 China
2. University of Chinese Academy of Sciences 19 A Yuquan Rd, Shijingshan District Beijing 100049 China
3. Max Planck Institute for Chemical Physics of Solids 01187 Dresden Germany
4. Department of Physics Indian Institute of Technology New Delhi 110016 India
5. Department of Physics Massachusetts Institute of Technology Cambridge MA 02139 USA