Design of ternary-component X-band microwave absorber based on FeCo/Sr hexaferrite/PANI nanocomposite in silicon resin matrix

Abstract

This work reports on the design and investigation of a new microwave absorber prepared from the combination of Sr-hexaferrite as a hard magnetic material, FeCo nanoparticles as a soft magnetic material, and polyaniline PANI as a dielectric-loss material. The prepared microwave absorber was characterized structurally and morphologically by X-ray diffractometry and scanning electron microscopy. The magnetic properties of the absorber were studied by vibrating sample magnetometer. Vector network analysis was used to perform the electromagnetic characterization of the absorber, which shows an excellent microwave absorption performance in the X-band. The minimum reflection loss was −22.1 dB at a matching frequency of 8.5 GHz, and the bandwidth under −10 dB was 2.6 GHz at a low loading percentage of 30 wt% and a thickness of 2 mm. The good microwave absorption characteristics were linked to the synergistic effect of combining magnetic and dielectric lossy materials. The effect of the chemical nature of silicon resin matrix on the microwave absorption performance was investigated. The presence of polar Si-O groups in silicon resin enhanced the minimum reflection loss and decreased the matching frequency.