[1] Jilin Univ, State Key Lab Superhard Mat, Changchun 130012, Peoples R China
[2] Mudanjiang Normal Univ, Sch Phys & Elect Engn, Key Lab New Carbon based Funct & Superhard Mat Hei, Mudanjiang 157011, Peoples R China
[3] Inner Mongolia Univ Technol, Coll Sci, Hohhot 010051, Peoples R China