Broadband and tunable high-performance microwave absorption properties by Ni-coated carbon fibers

Abstract

Composites of carbon fibers (CFs) and magnetic metals have concerned attention for tunable microwave absorption materials (MAMs). In this work, magnetic nickel (Ni) particles were coated on the CFs surface by an electroplating technique. Different morphology of Ni-coated CFs was established by setting the plating time. The microstructure, electric and magnetic properties, complex permittivity and permeability, and reflection loss (RL) of the Ni-coated CFs were specified as a function of the surface morphology of composites. SEM and EDX results displayed that Ni particles are uniformly deposited on the surface of CFs. Moreover, the Ni-coated CFs with different coating morphologies exhibit different microstructure. The creation of a magnetic Ni layer onto CFs improved composite properties, not only raising the saturation magnetization (17–46 emu/g) but also enhancing electrical conductivity (361–594 S/cm). The electromagnetic parameters and RL values of the Ni-coated CFs were investigated over the 2.0–18.0 GHz frequencies. The minimum RL could reach up to −64.8 dB at 14.9 GHz with 2.0 mm matching thickness and high effective bandwidth of 2.2–18.0 GHz. It has been displayed that the properties of Ni-coated CFs can be effectively controlled by changing the morphology of the Ni layer, which provides a novel route to fabricate Ni-coated CFs with tunable and broadband microwave absorption properties.