Synthesis and absorbing mechanism of two-layer microwave absorbers containing flocs-like nano-BaZn1.5Co0.5Fe16O27 and carbonyl iron

Flocs-like nano-barium ferrite (BaZn1.5Co0.5Fe16O27) was synthesized by sol–gel method using the absorbent cotton as template for the first time. A possible mechanism for the formation of flocs-like nano-barium ferrite had been proposed. Two-layer microwave nano-BaZn1.5Co0.5Fe16O27/carbonyl iron composite has been prepared by as-prepared material. The structure, morphology and properties of the composites are characterized with X-ray diffraction (XRD), scanning electron microscope (SEM), Net-work Analyzer. The complex permittivity and reflection loss (dB) of the composites have been measured at different microwave frequencies from 30 MHz to 6000 MHz employing vector network analyzer model PNA 3629D vector. The effect of the layer thickness of carbonyl iron on the microwave loss properties of the composites is investigated. A possible microwave absorbing mechanism of nano-BaZn1.5Co0.5Fe16O27/carbonyl iron composite has been proposed. The nano-BaZn1.5Co0.5Fe16O27/carbonyl iron composite can find applications in suppression of electromagnetic interference (EMI), and reduction of radar signature.

► Flocs-like BaZn1.5Co0.5Fe16O27 was synthesized for the first time.
► A possible formation mechanism for flocs-like ferrite had been proposed.
► Two-layer microwave composite has been prepared.
► A possible microwave absorbing mechanism of the composite has been proposed.