Magnetic Field‐Induced Orientation for Frequency‐Tunable and Ultrawide Broadband Microwave Absorption in Soft Magnetic Materials

Abstract Soft magnetic materials are promising candidates for low‐frequency electromagnetic (EM) wave absorption due to their high permeability and good processability. However, their inherently narrow effective absorption bandwidth (EAB) poses a major challenge for achieving broadband absorption and multi‐band frequency coverage. In this study, planar anisotropic FeSiCr soft magnetic alloys with parallel orientation characteristics are successfully fabricated via a magnetic field‐induced orientation strategy, coupled with the microstructural regulation of the flake‐like particles. The synergistic regulation of micromorphology, particle size distribution, and orientation enables precise tuning of the EM absorption frequency range covering the S, C, X, and Ku bands. Remarkably, at a 45° orientation angle, the material demonstrates dual‐peak absorption with an ultra‐wide EAB of 9.0 GHz and a strong minimum reflection loss of −62.4 dB. Experimental results and theoretical modeling further reveal that orientation architecture engineering facilitates a balance between combination of permittivity and permeability, thereby optimizing impedance matching. This magnetic field‐induced orientation alignment offers a promising strategy for designing frequency‐tunable, wide absorption bandwidth, customizable and low‐cost EM wave absorbers, offering new opportunities for practical applications in communication and radar systems.