Epoxy resin matrix nanocomposites with core-shell structure of NiZnFerrite/Ag and NiZnFerrite/PANi as fillers for microwave absorber in Ka-band

Abstract

The core-shell NiZnFerrite/Ag and NiZnFerrite/PANi (7:1 %wt) with epoxy resin forming a nanocomposite structure were synthesized by blending at 70 %vol content and introduced it into epoxy resin to be a microwave absorber. The phase and morphology characterization of the formation processes of NiZnFerrite/Ag and NiZnFerrite/PANi core-shell structure were studied using X-ray diffraction, transmission electron microscopy and scanning electron microscopy respectively. Microwave absorbing properties were investigated by reflectivity measurements in Ka-band (18-26 GHz). The reflection losses were calculated based on the model of a single layered plane wave absorber backed by a perfect conductor. The composite epoxy resin-NiZnFerrite/Ag shows matching frequency (f m1=20.7GHz and fm2=23.2GHz), maximum reflection loss (RLm1=-20.8dB and RLm2=-29.8dB) and bandwith (Δf1=18.6-21.7GHz and Δf2=21.7-25.0GHz ) Further, the composite epoxy resin-NiZnFerrite/PANi shows matching frequency (fm1=20.7GHz and fm2=23.2GHz), maximum reflection loss (RLm1=-20.1dB and RLm2=-24.6dB) and bandwith (Δf1=19.9-21.9GHz and Δf2=21.9-25.0GHz,) for an absorber thickness of 3.6 mm. © 2011 American Institute of Physics.