Preparation of BaZn_2 Fe_(16)O_(27) ferrite /graphite composite absorbent and its electromagnetic absorbing performance

W-type ferrite BaZn 2 Fe 16 O 27 prepared by the solid-state method was mechanically mixed with different content graphites to obtain compounded absorbent.The samples by a solid-state method were characterized by X-ray diffraction(XRD) and scanning electron microscopy(SEM).The results showed that the main phase of the powders was magnetoplumbite ferrite with a hexagonal shape.The microwave absorptive performance of the composite powders was studied from 2 to 12 GHz,and the reflection loss was simulated by the YRcompute software.The coordinate function of magnetic loss type ferrite and dielectric loss type graphite obviously improved the magnetic loss and dielectric loss of the composite powder,and optimized its absorbing properties.With the increase of the graphite content,the dielectric constant and the dielectric loss were increased.The maximum of the dielectric loss increased from 0.02 to 0.2,but the magnetic permeability and the magnetic loss firstly increased,then decreased.When the weight percentage content of graphite was 4%,the maximum reflection loss(RL)of the composite absorbent was about-40.6 dB at 5 GHz.Moreover,the absorption bandwidth reached 4 GHz when RL was less than-10 dB at Ku-band.