1. College of Physics and Electronic Engineering, Center for Magnetic Materials and Devices, Qujing Normal University , Qujing, 655011 , Yunnan China
2. College of Mechanical and Electrical Engineering, Mianyang Normal University , Mianyang , 621000, Sichuan , China
3. Public Experimental Teaching Center, Panzhihua University , Panzhihua , 617000, Sichuan , China