The synergistic regulation of micro sequence interface and macro bionic structure for superior microwave absorption performance

Micro-interface control and macro-structure design are crucial factors in achieving outstanding electromagnetic wave absorption (EMA) absorbers. However, it is still a challenge to obtain efficient EMA materials to satisfy practical applications through the synergistic regulation of the two. Herein, unique sequential interface engineering is proposed to ingeniously customize a series of FeCo nanochains (FC NCs) with various particle interface self-assembly combination modes, including face-to-face, corner-to-corner, and squeeze-to-squeeze. The dipole polarization, interfacial polarization, and magnetic coupling strength were enhanced to realize dielectric- magnetic synergies coupled with Ti3C2Tx MXene for exceptional EMA performance. The optimized squeeze-to- squeeze-shaped FeCo Nanochains/Ti3C2Tx MXene (FC3/MXene) exhibits the minimum reflection loss (RLmin) value of-60.95 dB at 1.897 mm and the reflection loss (RL) value of-51.46 dB at an ultralow thickness of 1.143 mm (The EMA efficiency exceeds 99.999 %). Additionally, a bionic periodic structure inspired by the sea urchin shell was designed based on the high-performance absorber FC3/MXene, achieving the impressive value of-64.48 dB and a whole absorption band covering 2-18 GHz, thanks to its isotropic structure and high porosity. Furthermore, in radar cross-section (RCS) simulations, FC3/MXene absorbers effectively reduce the radar detection distance of an unmanned aerial vehicle (UAV), demonstrating excellent stealth characteristics. Looking ahead, this work not only achieves strong RL intensity at ultralow thickness through sequential interface engineering but also obtains the super wide absorption band by bionic periodic structure design, opening new possibilities for diverse advanced technological applications.