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 morphology, 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, exhibiting stronger dielectric loss ability. The loss mechanisms to incident waves mainly include conductive loss, interfacial polarization loss, natural resonance and exchange resonance. •Three Fe20Ni80 particles with different morphologies were prepared.•The particles had the same structure and composition.•The three particles all shown low coercivity.•The impedance matching of worm-like particles was the highest.•Worm-like particles shown the strongest loss ability to EM waves.