Synthesis of core–shell structured tetra-needle ZnO whisker and Fe composite with excellent electromagnetic properties

Abstract

Core–shell structured T-ZnOw@Fe composite composed of a dielectric T-ZnOw core and a ferromagnetic Fe shell was synthesized using MOCVD method. Rough α-Fe shell was homogeneously deposited on the surface of T-ZnOw. The as-prepared composite exhibits excellent microwave absorption properties with the minimum reflection loss (RL) of −55.6 dB for a thickness of 1.48 mm and the broadest effective absorption bandwidth (less than −10 dB) of 4.56 GHz for a thickness of 1.55–1.66 mm. The enhanced electromagnetic performances are attributed to the enhanced interfacial polarization, natural resonance, and exchange resonance. The results imply that the deposition of α-Fe shell on T-ZnOw was an efficient way to fabricate lightweight and high-performance microwave absorption materials.