In Situ Dielectric Heterophase Engineering of Ternary Chelate Nanowire‐Derived CoFe/MnO@C Nanorods for High‐Efficiency Electromagnetic Wave Absorption

Nowadays, constructing heterogeneous interface engineering based on metal‐organic frameworks has become an effective strategy for enhancing electromagnetic response. Nevertheless, balancing magnetic–dielectric synergistic effects among components and achieving strong wideband electromagnetic wave (EMW) absorption remains a challenge. Herein, heterostructure CoFe/MnO@C nanorods (CFM@C) assembled from carbon‐coated magnetic/dielectric dual core nanocapsules were fabricated by calcining ternary metal chelates. Interestingly, the metal ions did not form a ternary alloy, but rather Mn transformed into MnO and embedded as the dielectric heterophase in the CoFe magnetic core. Thanks to the multipolarization enhancement and magnetoelectric synergistic effect, the EMW attenuation ability of CFMC nanorods is enhanced and their impedance matching is optimized. Compared to CoFe@C, CFM@C exhibits superior EMW absorption performance with a minimum reflection loss (RL) of −52.42 dB and an effective absorption bandwidth (EAB) of 7.36 GHz. Excitingly, the gradient multilayer structural design obtained from computer simulation technology (CST) simulation can extend EAB to 10.31 GHz. Radar cross‐section (RCS) simulation result demonstrates that the maximum RCS reduction is 25.56 dB at 0°, demonstrating its strong radar wave attenuation ability. Therefore, the CFM@C nanorods demonstrate promising practical applications and this study provides an innovative strategy for constructing strong broadband EMW absorbers.