1. School of Materials Science and Engineering, University of Science and Technology of Beijing, Beijing 100083, People's Republic of China
2. School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, United Kingdom
3. XiaMen Tungsten Co. Ltd., No. 619 Hubin South Rd., Xiamen, Fujian 361004, People's Republic of China
4. State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China