Electromagnetic and microwave absorbing properties of Ni0.5Zn0.5Fe2O4/bamboo charcoal core–shell nanocomposites

Abstract Bamboo charcoal coated with nanoparticles Ni0.5Zn0.5Fe2O4 spinel ferrite, forming a core–shell structure, were synthesized by utilizing hydrothermal method at different bamboo charcoal content (10, 20 and 30 wt%) and introduced into epoxy resin to be a microwave absorber. Structural characterization by Fourier transform infrared, X-ray diffraction, scanning electron microscopy and transmission electron microscopy proved that nanometer-sized Ni0.5Zn0.5Fe2O4 in the composites was responsible for the ferromagnetic behavior of the composites. The electromagnetic properties of the Ni0.5Zn0.5Fe2 O4/bamboo charcoal composites exhibited super-paramagnetic behavior and low blocking temperatures. The reflection loss of composites measured in the microwave frequency range of 2–18 and 18–40 GHz showed that microwave absorbing properties of the Ni0.5Zn0.5Fe2O4/bamboo charcoal composite were higher than that of Ni0.5Zn0.5Fe2O4 and bamboo charcoal.