[1] Nanjing Univ Aeronaut & Astronaut, Dept Appl Phys, Nanjing 210016, Peoples R China
[2] China Jiliang Univ, Dept Mat Engn, Hangzhou 310018, Zhejiang, Peoples R China
[3] Chinese Acad Sci, High Field Magnet Lab, Hefei 230031, Peoples R China
[4] Univ Sci & Technol China, High Field Magnet Lab, Hefei 230026, Peoples R China