[1] Nanjing Univ Sci & Technol, Sch Mat Sci & Engn, Nanjing, Peoples R China
[2] Nanjing Univ Sci & Technol, Herbert Gleiter Inst Nanosci, Nanjing, Peoples R China
[3] Univ Lahore, Dept Phys, Sargodha Campus, Sargodha, Pakistan
[4] Nanyang Polytech, Sch Engn, Singapore, Singapore
[5] NJUST, Northern Res Inst, Tianjin, Peoples R China