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 (fm1 = 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.