In situ surface modification engineering for synthesizing nano-absorbers with self-forming heterointerfaces and prominent electromagnetic wave absorption

Abstract

It is usually necessary to construct core–shell structures for Fe-based electromagnetic wave absorbers (EMWAs) by applying multi-step physical or chemical methods owing to their poor impedance matching characteristics. However, effectively and simply modifying surfaces remains challenging. Herein, an in situ surface modification strategy was proposed to solve the above issue by synthesizing nano-absorbers with core and self-forming shells via a one-step method. The synergy of the nano-size and heterointerface in nanoscale core–shell structure led to moderate impedance matching and multiple attenuation mechanisms, resulting in outstanding absorption ability. The minimum reflection loss (RL_min) of −52.93 dB at 12.95 GHz and an effective absorption band (EAB) of ∼5.01 GHz were achieved at 2 mm. Furthermore, an ultra-thin thickness of 1.5 mm is capable to result in a strong RL_min (−48.09 dB at 16.60 GHz) with a wide EAB (4.61 GHz). The radar cross-section simulation confirmed that the nano-absorbers could drastically reduce the radar echo, making them potential radar stealth materials. This work verifies a facile strategy for fabricating high-performance EMWAs with a core–shell structure that could practicality reduce electromagnetic pollution and achieve antiradar stealth.