Synthesis and electromagnetic properties of Fe3S4 nanoparticles

Fe3S4 nanoparticles with a narrow diameter distribution of 50 nm have been synthesized by an environmentally benign chemical method and the electromagnetic properties were investigated in the frequency range of 0.03–18 GHz. Theoretical approach, based on the Cole–Cole semicircle, evidently indicates that the dielectric relaxation process corresponds to the Debye dipolar relaxation, meanwhile accompanying with a suppressed eddy current phenomenon. Additionally, Fe3S4 nanoparticles possess significant magnetic losses mainly arising from the natural resonance, resulting in an ideal electromagnetic match. The reflection loss is optimized to be −36.03 dB at 12.61 GHz for a Fe3S4-paraffine composite layer of 3.0 mm in thickness. The electromagnetic absorption properties are ascribed to a synergetic effect of dielectric loss, magnetic loss and the quarter-wavelength cancellation.