Xu-Yang Wang, Qian-Nan Li, Yue-Kun Wang, Dan Liu, Yong-Mei Liang, Ya-Qiang Li, Dong-Xiao Ma, Guang-Qian Zhu, Yao-Li Ji, Guang-Sheng Wei, Bao-Chen Han
Breakthroughs in electrification, intelligent systems, and carbon-neutral technologies are driving an urgent demand for soft magnetic materials that simultaneously deliver high saturation magnetic flux density (Bs), low coercivity (Hc), large effective permeability ($\mu$e), and superior high-frequency stability. Fe-based amorphous and nanocrystalline alloys uniquely combine these attributes with excellent thermal stability and mechanical robustness, positioning them as prime candidates for next-generation energy systems. However, the composition-structure-property relationship remains only partially understood, and scalable strategies to translate laboratory performance into industrial deployment are still underdeveloped. To address these challenges, a unified framework integrating magnetic theory, microstructural design, and emerging computational methodologies is established. The roles of grain size, amorphous/nanocrystalline coupling, and alloying strategies in governing Bs, Hc, $\mu$e, and Curie temperature (Tc) are elucidated by linking classical models (Herzer's random anisotropy, Suzuki's coupling) with density functional theory and machine learning driven predictions. Representative fabrication routes, including rapid solidification, magnetic-field annealing, spark plasma sintering, and additive manu-facturing, are critically assessed in terms of both performance optimization and scalability. Notably, Fe-based nanocrys-talline alloys such as FINEMET and NANOPERM achieve Bs Bs>1.5T, Hc<10 A/m, and core-loss reductions of 40%-70% relative to Si-steel, enabling high-efficiency transformers and power converters. A forward-looking roadmap is concluded for developing low-cost, high-performance Fe-based soft magnetic materials, bridging fundamental research and industrial application.
