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