Directional control of electromagnetic parameters of Fe@Ni nanowires for ultrathin and low-frequency microwave absorbing

How to prepare materials according to the target properties has been a hot research topic. In this paper, the target electromagnetic parameters are obtained according to the performance requirements, and the nanoflower rod-like, low-density mulberry-like and high-density mulberry-like one-dimensional (1D) core–shell structured Fe@Ni ( x ) nanowires (NWs) are prepared by liquid-phase reduction method. The effective absorption bandwidth (EAB) of sample Fe@Ni (40) in the low-frequency (2–8 GHz) is up to 1.89 GHz (3.1 mm). Sample Fe@Ni (60) is able to reach a maximum EAB of 3.18 GHz at a thickness of 0.9 mm. Concisely, the sample has the ability to absorb microwaves in low frequency bands and ultra-thin thicknesses. The reason can be attributed to the strong magnetic coupling brought by the bimetallic composition to strengthen the resonance level and the excellent 1D core–shell structure to enhance the efficiency of polarization loss. In conclusion, Fe@Ni ( x ) provides a technological route for the preparation of low-frequency and ultra-thin-thickness absorbers.