The rapid advancement of modern electronics, telecommunications, and artificial intelligence has driven an urgent demand for high-performance soft magnetic materials, particularly those compatible with third-generation semiconductors. These semiconductors, characterized by wide bandgaps, high breakdown fields, and superior thermal conductivity, enable power devices to operate at higher frequencies (>1 MHz) and power densities. However, traditional soft magnetic materials, such as silicon steels and ferrites, face inherent trade-offs between critical properties: saturation magnetization (B_s) versus coercivity (H_c), permeability versus core loss, and mechanical strength versus magnetic "softness." These limitations hinder their application in emerging high-frequency, high-efficiency scenarios. Amorphous soft magnetic materials, with their unique hierarchical ordered structures spanning atomic to nanoscales, offer a revolutionary platform to overcome these trade-offs. These materials exhibit rich physical properties governed by short-range order (SRO, <0.5 nm), medium-range order (MRO, 0.5-2 nm), and amorphous-nanocrystalline dual-phase architectures. The concept of order modulation—strategically tailoring the intrinsic characteristics (e.g., cluster density, topological configuration) and spatial arrangements of these ordered structures—has emerged as a transformative approach to decoupling conflicting material properties. This review systematically examines the following key aspects:
1. Historical evolution of soft magnetic materials
From early silicon steels and ferrites to modern amorphous and nanocrystalline alloys, the development of soft magnetic materials has paralleled advancements in power electronics. The advent of Fe-based amorphous alloys and Finemet-type nanocrystalline alloys marked milestones in achieving high B_s (>1.6 T), ultra-low H_c (<1 A/m), and reduced core losses at high frequencies. However, performance bottlenecks persist near theoretical limits, necessitating innovative strategies.
2. Theoretical foundations of order modulation
Order parameter theory: Landau’s phase transition theory and synergetics elucidate how magnetic order parameters govern macroscopic properties. In amorphous alloys, magnetic interactions are dominated by SRO clusters and their MRO arrangements.
Magnetism-structure relationships: advanced techniques, such as atomic electron tomography (AET) and synchrotron pair distribution function (PDF) analysis, reveal that SRO/MRO structures directly influence exchange coupling, magnetic anisotropy, and domain wall dynamics. For instance, Fe-M (M = Si, B) clusters with dense packing enhance B_s, while MRO homogenization reduces H_c.
3. Advances in order-modulated amorphous soft magnetic materials
Atomic-scale modulation: elemental doping (e.g., Co, Mo, Cu) and energy-field treatments (e.g., magnetic annealing, ultrasonic vibration) optimize local atomic configurations. For example, ultrasonic processing of Fe78Si9B13 ribbons induces stress relaxation, forming 2-3 nm Fe-M clusters that boost B_s to 183.2 emu/g while maintaining H_c at 4.2 A/m.
Nanoscale dual-phase design: controlled crystallization of α-Fe(Si) nanocrystals (<15 nm) within an amorphous matrix creates exchange-coupled nanocomposites. Co-Mo co-doping in FeSiBCuNb alloys refines grain size to 11.8 nm, achieving a permeability of 65,000 at 100 kHz—44% higher than conventional Finemet alloys.
Interface engineering in soft magnetic composites (SMCs): core-shell architectures (e.g., FeSiB@FeB nanoparticles) with stress-buffering interfaces reduce eddy current losses while preserving permeability. Cold sintering of vortex-domain FeSiAl powders enables GHz-range operation with stable permeability (μ_i=13 at 1 GHz).
4. Future directions and challenges
Machine learning-driven design: integrating high-throughput simulations and AI models (e.g., XGBoost, random forests) accelerates the discovery of optimal compositions and order parameters. Recent work predicts B_s using Fe content, mixing enthalpy, and electronegativity differences, guiding the synthesis of (Fe₈₂Co₁₈)_85.5Ni_1.5B₉P₃C₁ alloys with B_s =1.92 T.
Novel magnetic topologies: magnetic vortex structures and skyrmion-like configurations in ultrafine powders show promise for ultra-high-frequency applications (>100 MHz).
Low-stress manufacturing: innovations like ultrasonic rheoforming reduce compaction pressures by 99% (to 6.2 MPa), mitigating residual stress and enhancing SMC performance.
In situ characterization: neutron scattering and grating-based imaging techniques enable real-time observation of domain dynamics under operational conditions (e.g., stress, magnetic fields).
In conclusion, order modulation represents a paradigm shift in soft magnetic material design, bridging atomic-scale interactions to macroscopic performance. By leveraging multi-scale ordered structures and advanced manufacturing technologies, next-generation amorphous-based materials are poised to revolutionize high-frequency power electronics, electric vehicles, and AI-driven systems. However, challenges in scalable production, cost-effective processing, and standardized evaluation must be addressed to accelerate industrial adoption.