Morphology modulation induced enhancement of microwave absorption performance in Fe20Ni80 particles

Exploring the influence of material morphology on microwave absorption performance is of significance for designing high performance absorbers. A feasible coprecipitation strategy was proposed for preparing three kinds of Fe20Ni80 particles with different morphologies (ball-like, worm-like and flower-like). The mor-phology, structure and performance of the particles were contrastively studied. The results showed that the morphology had a remarkable effect on microwave absorption performance. Under the same structure and composition, the performance of worm-like particles was obviously better than that of other particles. Particularly, under the filler loading of 20 wt%, the minimum reflection loss (RLmin) value reached - 48.5 dB at 7.9 GHz, and the maximum effective absorption bandwidth (EABmax) was 4.3 GHz (8.3-12.6 GHz) with a matching thickness of 2.5 mm. The arrangement of worm-like particle resembles a chaotic porous nest, which optimizes impedance matching. In addition, the worm-like particle has a large aspect ratio, ex-hibiting stronger dielectric loss ability. The loss mechanisms to incident waves mainly include conductive loss, interfacial polarization loss, natural resonance and exchange resonance.(c) 2022 Published by Elsevier B.V.

Automated summary

Exploring the influence of material morphology on microwave absorption performance is important for designing high-performance absorbers. In this study, a feasible coprecipitation strategy was used to prepare three types of Fe20Ni80 particles with different morphologies (ball-like, worm-like, and flower-like). The morphology, structure, and performance of the particles were compared and analyzed. The results showed that the worm-like particles had significantly better microwave absorption performance compared to the other particles. The arrangement of the worm-like particles optimized impedance matching and their large aspect ratio exhibited strong dielectric loss ability.