1. Key
State Laboratory of Superhard Materials, Jilin University, Changchun, 130012, P.R. China
2. College
of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, 310014, P. R. China
3. Department
of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 Canada
4. Department
of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 Canada