Achieving Ultra-Broadband and Enhanced Microwave Absorption in the Ku-Band via Hierarchical Fe۳O۴@N,P- Codoped Carbon/Polyaniline Heterostructures

This study presents the design, synthesis, and superior microwave absorption performance of a hierarchical core-shell heterostructure, denoted as Fe۳O۴@NP-C/PANI. The composite integrates hollow Fe۳O۴ microspheres coated with a nitrogen and phosphorus co-doped carbon shell (Fe۳O۴@NP-C) with a conductive polyaniline (PANI) matrix. This architecture synergistically combines magnetic loss, dielectric loss, and conduction loss mechanisms. The Fe۳O۴@NP-C/PANI composite exhibits exceptional microwave absorption properties in the Ku-band (۱۲-۱۸ GHz), achieving a remarkable minimum reflection loss (RLmin) of -۷۴.۳ dB at ۱۴.۲ GHz with a thin matching thickness of only ۲.۴ mm. Furthermore, it demonstrates an ultra-wide effective absorption bandwidth (EAB, RL < -۱۰ dB) of ۵.۸ GHz, spanning from ۱۲.۲ to ۱۸.۰ GHz, effectively covering the entire Ku-band. The outstanding performance is attributed to optimized impedance matching via PANI incorporation and multi-scale polarization effects arising from the hetero-interfaces, defect sites in the doped carbon shell, and the conductive PANI network. This work provides a novel strategy for developing high-performance, lightweight, and broad-bandwidth microwave absorbers for next-generation electronic and stealth applications.

کلیدواژه ها:

Microwave Absorption ، Core-Shell Structure ، Fe۳O۴ ، Heteroatom Doping ، Polyaniline ، Ku-Band ، Impedance Matching