Nanocomposites of Oriented Nickel Chains with Tunable Magnetic Properties for High-Performance Broadband Microwave Absorption

Chainlike nickel nanostructures were prepared by using an efficient wet chemical method, and Ni/polyvinylidene fluoride (PVDF) composites were fabricated with a rotational orientation in a static magnetic field. The oriented magnetic nanochains in the composites show a uniform distribution without significant agglomeration, which favors the impedance matching and attenuation ability of the absorbents. The Ni/PVDF composite with only a 20 wt % loading of oriented nickel chains exhibits a minimum reflection loss (RL) value of −36.8 dB at 23.2 GHz from 18 to 26.5 GHz, while an optimal RL of −37.3 dB is obtained at 35.6 GHz with a 10 wt % loading from 26.5 to 40 GHz. Moreover, an excellent electromagnetic interference shielding effectiveness (35 dB) is achieved with an oriented filler loading of 30 wt %. Rotational orientation is an effective strategy for magnetic materials to achieve enhancements in both microwave absorption and shielding performance.