Preparation and electromagnetic and microwave absorbing properties of Fe-filled carbon nanotubes

Abstract The carbon nanotubes (CNTs) were filled with Fe nanoparticles via a wet-chemical method. Microwave absorption, complex permittivity and permeability of the Fe-filled CNTs have been investigated. The real part ( ɛ ′) and imaginary part ( ɛ ″) of the permittivity of the Fe-filled CNTs are smaller than those of CNTs. While the real part ( μ ′) and imaginary part ( μ ″) of the permeability and the magnetic dissipation factors tg  δ μ ( μ ″/ μ ′) of the Fe-filled CNTs are bigger than those of CNTs. The Fe-filled CNT/epoxy composites achieved a reflection loss below −10 dB (90% absorption) at 11.8–14.7 GHz, and the minimum value is −31.71 dB at 13.2 GHz. The microwave enhancement absorption of Fe-filled CNT/epoxy composites was attributed to both dielectric and magnetic losses. The microwave-absorbing peak of the CNT/epoxy composites moves to the higher frequency by filling the Fe nanoparticles into the CNTs.