Research Progress on the Creation of High-Frequency Amorphous-based Soft Magnetic Materials by Order Modulation Engineering

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 (<i>B_s</i>) versus coercivity (<i>H_c</i>), 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:<br> <b>1. Historical evolution of soft magnetic materials</b> <br>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 <i>B_s</i> (>1.6 T), ultra-low <i>H_c</i> (<1 A/m), and reduced core losses at high frequencies. However, performance bottlenecks persist near theoretical limits, necessitating innovative strategies.<br> <b>2. Theoretical foundations of order modulation</b> <br>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.<br>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 <i>B_s</i>, while MRO homogenization reduces <i>H_c</i>.<br> <b>3. Advances in order-modulated amorphous soft magnetic materials</b> <br>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 <i>B_s</i> to 183.2 emu/g while maintaining <i>H_c</i> at 4.2 A/m.<br>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.<br>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 (<i>μ_i</i>=13 at 1 GHz).<br> <b>4. Future directions and challenges</b> <br>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 <i>B_s</i> using Fe content, mixing enthalpy, and electronegativity differences, guiding the synthesis of (Fe₈₂Co₁₈)_85.5Ni_1.5B₉P₃C₁ alloys with <i>B_s</i> =1.92 T.<br>Novel magnetic topologies: magnetic vortex structures and skyrmion-like configurations in ultrafine powders show promise for ultra-high-frequency applications (>100 MHz).<br>Low-stress manufacturing: innovations like ultrasonic rheoforming reduce compaction pressures by 99% (to 6.2 MPa), mitigating residual stress and enhancing SMC performance.<br>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).<br>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.