Enhanced electromagnetic wave absorption of olive-like Fe3O4/Fe@C core-shell nanocomposite in Ku band

Core-shell structure is an effective approach to modulate the impedance matching behaviour and induce polarization relaxation at the interface for the high-performance electromagnetic wave absorption (EMWA) materials. Herein, core-shell structures of Fe 3 O 4 –Fe@C (FFC) were successfully developed by hydrothermal and thermal decomposition methods. The results showed that the phase composition, microstructure and EMWA performance were tailored by the heat treatment process. The optimized FFC hybrid exhibited a minimum reflection loss ( RL ) value of −56.3 dB with a matching thickness of 1.99 mm, and the effective bandwidth ( RL   < −10 dB, 5 GHz) covers almost the whole Ku band. The enhanced EMWA properties of the reinforced olive-like composites were mainly ascribed to the magnetic loss derived from the enhanced magnetic anisotropy, and the dielectric loss originated from the multilevel interface and polarization characteristics between the core and the shell. Therefore, this work provides an approach to design core-shell nanocomposites with enhanced EMWA performance.