Electromagnetic and microwave absorbing properties of carbonyl iron/BaTiO3 composite absorber for matched load of isolator

Composite absorbers made from carbonyl iron powder and BaTiO3 were prepared by blending technique with the matrix of epoxy resin. The structure and microtopography of the carbonyl iron and BaTiO3 particles were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The microstructure and electromagnetic properties of the as-prepared composites were investigated by SEM and vector network analyzer (VNA). The effect of the mass ratio of BaTiO3/carbonyl iron on the electromagnetic properties of the composites is investigated. The bandwidth with an absorption loss exceeding 30 dB is obtained in the whole measured frequency range for all composites, and an optimal reflection loss drop below 1.5 dB with 24 wt% BaTiO3. It is found that the carbonyl iron/BaTiO3 composite absorber can be a promising candidate as a matched load for the isolator.