Electromagnetic attenuation distribution in a three-dimensional amorphous carbon matrix with highly dispersed Fe/Fe3C@graphite-C nanoparticles

• Published in: Materials & design Vol. 216; p. 110528
• Main Authors: Dong, Wenqi, Li, Xueai, Tang, Huimin, Shi, Kai, Wang, Chunsheng, Guo, Wanchun, Tian, Kesong, Wang, Haiyan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2022; Elsevier
• Subjects: Carbon nanoflakes; Distribution of electromagnetic attenuation; Fe/Fe3C@graphite-C; Microwave absorption; Numerical simulation; Numerical simulation; Microwave absorption; Carbon nanoflakes; Distribution of electromagnetic attenuation; Fe/Fe3C@graphite-C
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2022.110528

[Display omitted] •A 3D amorphous carbon matrix with dispersed Fe/Fe3C@graphite-C nanoparticles was synthesized by a facile route.•The synthesized composites had an RLmax of −69.0 dB and an effective reflection bandwidth (RL ≤ -10 dB) of 7.06 GHz.•Numerical simulation revealed the critical factors for enhanced microwave absorption in the hierarchical structure of composites.•The distribution of electromagnetic attenuation in composites contributes to the design of microwave absorbing materials. The dielectric-magnetic synergistic effect can be achieved by dielectric relaxation and magnetic resonances in composites of carbon materials and magnetic particles. However, there is no direct evidence demonstrating the distribution of electromagnetic energy attenuation in the microstructure of composites. Herein, an amorphous carbon matrix with dispersed Fe/Fe3C@graphite-C was fabricated via a facile route. The distribution of the magnetic vector loss and electric vector loss in the hierarchical structures was revealed by numerical simulation. The content and dispersion of magnetic particles as well as the morphology of the amorphous carbon can be tuned. The 3D amorphous carbon matrix with highly dispersed Fe/Fe3C@graphite-C nanoparticles provided the strongest absorption of −69.0 dB and an effective response bandwidth (RL ≤ −10 dB) of 7.06 GHz. The numerical simulation revealed that the magnetic vector loss originated only from the core of Fe/Fe3C, and the electric vector loss was distributed throughout the structure, especially in the graphite-C shell, the interface between graphite-C and carbon nanoflakes, and the junction of different carbon nanoflakes. This work not only reveals the distribution of electromagnetic loss but also supports the theoretical analysis of the electromagnetic wave attenuation mechanism in composites, which provides direction for the future design of composites.