Coal-based carbon/FeCo magnetic composites with layered stripes as novel light-weight microwave absorber

The introduction of magnetic materials into carbon materials has been proved to be an effective approach to tailor and improve electromagnetic wave (EM) absorption. In this study, coal-based carbon/FeCo (CBC/FeCo) magnetic composites were designed and prepared. These samples exhibit layered stripes similar to graphite. In these novel composites, the FeCo alloy exhibits strong magnetic loss and the coal-based carbon (CBC) not only acts as an impedance matching medium but also exhibits excellent dielectric loss. Therefore, the CBC/FeCo composites exhibit strong EM absorption, with minimum reflection loss ( RL min ) of −60.81 and −49.82 dB at thicknesses ( d ) of 1.38 and 2.45 mm, respectively. Compared with pure coal-based carbon and FeCo alloy, the improvement in EM absorption can be mainly attributed to the improved impedance matching and enhanced multiple interfacial polarization . In addition, the effects of reaction temperature and the content of FeCo on EM absorption performance of the composites were also studied. Specifically, samples of S-2 with process temperature at 800 °C for 2 h and the FeCo alloy mass loading was 0.3 g (CBC/FeCo-0.3), the EM absorption performance was optimized. It is believed that the CBC/FeCo composites could be promising candidates for EM absorbers.