Atomic‐Scale Customization of Oriented Dipolar Defects in Amorphous Carbon via Nanoparticle‐Templated Phase Engineering

Abstract Amorphous materials possess abundant local dipoles, however, spatial disorder leads to random orientations and restricted mobility, suppressing macroscopic polarization and limiting dielectric performance, thereby severely constraining their use in ferroelectrics, electromagnetic shielding, energy storage, and related applications. To address this challenge, a template‐assisted phase evolution strategy is proposed by loading monodispersed Fe ₃ O ₄ nanoparticles (≈10 nm) onto representative biomass‐derived amorphous carbon, followed by controlled carbothermal treatment. Interfacial reactions between the oxide and carbon generated nanopores, with pore edges enriched in quantifiable, highly oriented polar bonds. Meanwhile, the oxide nanoparticles evolved into yolk–shell structures with adjustable internal voids. These oriented dipoles enabled an active response to external high‐frequency EM fields, resulting in pronounced dielectric relaxation behavior and a sharp ≈60% enhancement in permittivity, as confirmed by frequency‐dependent dielectric measurements and theoretical calculations. The significantly improved dielectric polarization broadened their application in EM protection, achieving >90% absorption efficiency over a 5.6 GHz bandwidth and far exceeding that of typical carbon‐based composites. This work provides a versatile strategy for unlocking orientational polarization in amorphous systems, paving the way for advanced applications in electromagnetic wave absorption, energy storage, and adaptive electronics.