Surface morphology of magnetic carbon foam regulated electromagnetic properties for microwave absorption

Abstract

Electromagnetic pollution resulting from the electronic communication can be mitigated by using microwave absorbers. The magnetic N-doped carbon foams with diverse surface morphologies as absorbers were synthesized via alkalization treatment, hydrothermal reaction, and carbothermic reduction reaction. The microstructure, electromagnetic parameters, and microwave absorption properties can be tailored by adjusting thermal treatment temperatures. The results indicated that the composites exhibit exceptional microwave absorption properties, with a minimum reflection loss of −44.15 dB at 11.18 GHz and an effective absorption bandwidth of 5.3 GHz at a thickness of 1.53 mm. The exceptional microwave absorption properties can be attributed to the synergistic effect of superior impedance matching, robust dielectric loss, and magnetic loss. The far-field radar cross section (RCS) is also reduced, achieving a maximum RCS reduction value of 14.6 dBm2. The present study presents a novel concept for the fabrication of lightweight and broadband microwave absorbing materials.