Helical Conductive Pathways Bridge Polarization Centers at Hollow‐Confined Metal/N‐C Interfaces to Form a Coherent Electromagnetic Loss Network

ABSTRACT

Lightweight microwave absorbers are needed for electromagnetic interference mitigation, wireless communication protection, and radar scattering control. Carbon metal heterostructures integrate conductive networks, interfacial polarization, and cooperative magnetic dissipation; however, dense shell stacking can induce premature reflection and surface current accumulation, causing dielectric loss to depend excessively on conductive loss. Helical configurations are introduced to extend tortuous conductive pathways, and cavity‐enabled spatial decoupling is integrated with helical‐pathway reconnection through a scaffold‐guided growth‐reconstruction‐conversion strategy. The hollow space separates the helical CNC backbone from the surrounding CoNi/N‐doped carbon domains, reducing compact conductive stacking and facilitating microwave entry. The helical pathway reconnects distributed metal/N‐C polarization centers and extends induced current pathways, while its chiral topology may provide a geometric basis for potential cross‐polarization‐related interactions. Under microwave excitation, these centers form an impedance‐compatible coherent electromagnetic loss network that couples wave entry with volumetric dissipation. At their respective matching thicknesses, the optimized absorber achieves a minimum reflection loss of −54.80 dB and a maximum effective absorption bandwidth of 6.29 GHz. Complete Ku‐band and near complete X‐band coverage are obtained at optimized thicknesses, and simulations show reduced radar scattering. This work provides a design principle for broadband microwave absorbers and other wave functional heterostructures.