Nanoscale Dielectric Gene Dual‐Regulations in High‐Entropy Materials for Enhanced Electromagnetic Wave Absorption Over Low‐Mid Frequency

The demand for low‐mid frequency electromagnetic wave absorption (EWA) materials over 5G commercial bands is urgently increasing recently. However, the unpredictable parameter fluctuations in low‐mid frequency EWA performance make it difficult to realize effective microstructure/microcomponent designing. To this end, a feasible strategy is proposed to reasonably optimize the nanoscale dielectric characteristics in high‐entropy materials (HEM). The synergistic grain refinement and lattice distortion enable us to precisely match electromagnetic parameters, therefore enhancing dielectric loss that covers the low‐mid frequency absorption band. In detail, Mn‐doped carbon‐coated high‐entropy alloy nanoparticles (Mn‐HEA@C) allow for enhanced grain refinement, increased grain boundaries and phase interfaces, thereby triggering improved interface polarization and conductive loss. Meanwhile, the increased lattice distortion introduces defect‐induced dipoles that contribute to enhanced relaxation losses. Collectively, Mn 1 ‐HEA@C realizes efficient coverage of 5G low‐frequency communication bands (N77/78/79) with an effective absorption bandwidth (EAB) of 4.76 GHz, noticeably showing strong absorptions of −50.7 dB at 11.71 GHz and −43.4 dB at 4.91 GHz, respectively. These new findings suggest the nanoscale dielectric gene dual‐regulation strategy greatly contributes to optimized impedance matching and electromagnetic attenuation and lay solid foundations for novel absorbers that emphasize on low‐mid frequency absorption.