[1] Taiyuan Univ Technol, Coll Mat Sci & Engn, Taiyuan 030024, Peoples R China
[2] Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, CAS Key Lab Magnet Mat & Devices, Ningbo 315201, Zhejiang, Peoples R China
[3] Taiyuan Univ Technol, Dept Phys, Taiyuan 030024, Shanxi, Peoples R China
[4] Jiangnan Univ, Sch Sci, Wuxi 214122, Peoples R China
[5] Nanjing Univ, Natl Lab Solid State Microstruct, Nanjing 210093, Jiangsu, Peoples R China
[6] Nanjing Univ, Key Lab Nanomat Jiang Su Prov, Nanjing 210093, Jiangsu, Peoples R China
[7] Taiyuan Univ Sci & Technol, Dept Phys, Taiyuan 030024, Shanxi, Peoples R China