Magnetic array vertically anchored on flexible carbon cloth with magical angle for the increased effective absorption bandwidth and improved reflection loss simultaneously

Increasing electromagnetic pollution has put new demands on the development of high-performance microwave absorbing materials. In this paper, for the first time, a highly conductive flexible carbon cloth-based (CC-based) substrate is realized to tune the structure of the material at the macroscopic scale (centimeter-scale). The change of stacking mode is found to play a crucial role in the response behavior of electromagnetic waves of CC. When the stacking angle is 45 degrees, the CC is more prone to phase-to-cancellation behavior. Bimodal absorption occurs in the 2-18 GHz frequency band and succeeds in tripling its effective absorption bandwidth (from 2.24 GHz to 7.44 GHz). The in situ growth of magnetic mace-like NiCo2O4 on CC further breaks the limitation of a single loss mechanism inside CC and innovatively enables the construction of centimeter-scale microcurrent networks and magnetic coupling networks. Moreover, the 1D nanopin arrays anchored on CC substrates also help to provide numerous heterostructures with strong interfacial polarization behaviors, multiple scattering points, and good impedance matching capability, further improving the microwave absorption performance. Thus CC@NiCo2O4 achieves a reflection loss (RL) value of-54.1 dB at 14.08 GHz with an effective absorption bandwidth (EAB) of 6.3 GHz (11.7-18 GHz) at a thickness of only 2 mm. This work provides new ideas for the design and preparation of high absorption capacity and wide broadband response from both macroscopic and microscopic scales.

Automated summary

In this paper, a flexible carbon cloth-based substrate is introduced to tune the structure of the material at the macroscopic scale. The stacking mode and the in situ growth of magnetic mace-like NiCo2O4 on the carbon cloth are found to play crucial roles in the electromagnetic wave response behavior and the microwave absorption performance. The 1D nanopin arrays anchored on the carbon cloth further improve the microwave absorption performance. This work provides new ideas for the design and preparation of high absorption capacity and wide broadband response.