Facile synthesis and electromagnetic wave absorption properties of magnetic carbon fiber coated with Fe–Co alloy by electroplating

Magnetic carbon fiber coated with Fe–Co alloy was prepared by electroplating at 25 °C for 5 min. The obtained magnetic coatings show sheet-like morphology and the crystal structure of the uniform coating is Co3Fe7 with a thickness of about 0.5 μm. The saturation magnetization of the magnetic carbon fiber reaches 31.5 emu/g with a coercivity of 87.1 Oe. The complex permittivity and permeability of magnetic carbon fiber/paraffin (30 wt%) composite were measured in the 2–18 GHz frequency range. The reflection loss below −10 dB covers the whole frequency range while below −20 dB the absorption frequency bandwidth is 6.8 GHz, and the minimum value is −48.2 dB at a coating thickness of 1.7 mm. Magnetic carbon fiber exhibits excellent electromagnetic wave absorption properties.

Research highlights
► Magnetic carbon fiber coated with Fe–Co alloy is prepared by electroplating, which is simple, time saving and without using any toxic reductant or solvent.
► The magnetic alloy coatings show sheet-like morphology, and temperature plays a key role in controlling the coating morphology.
► Fe–Co alloy coated carbon fiber by electroplating seems very attractive for a thin, light and easy for production EMA material with strong and wide absorption.