* Corresponding authors

^a Division of Functional Materials, Central Iron and Steel Research Institute, Beijing, China
E-mail: zhengliyun@126.com, weili@cisri.com.cn

^b College of Materials Science and Engineering, Hebei University of Engineering, Handan, Hebei 056011, China

^c Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
E-mail: hmzheng@lbl.gov

^d Department of Electrical Engineering and Computer Science, Ningbo University, Ningbo, Zhejiang 315211, China

^e National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

^f Institute of Physics, Chinese Academy of Science, Beijing 100190, China

^g State Key Laboratory of Rare Earth Permanent Magnetic Materials, Hefei, Anhui 340124, China

^h Earth-Panda Advance Magnetic Materials Co., Ltd, Hefei, Anhui 340124, China

ⁱ Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA