Fabrication and electromagnetic properties of novel FeNi alloy-coated flake graphite prepared by electroless plating

In this paper, FeNi alloy-coated flake graphite (FeNi-FG) was prepared by electroless plating technique using hydrazine as reducer. Several analytical techniques including scanning electron microscopy (SEM), optical microscope (OM), energy dispersive spectroscopy (EDS), transmission electron microscope (TEM), X-ray diffraction (XRD) are systematically employed to characterize the FeNi-FG. The results show that the pretreated flake graphite is fully wrapped by FeNi alloy which consist of FeNi3 phase, and the formed FeNi-FG possesses saturation magnetization of 37.5emu/g. The paraffin-based composite filled with FeNi-FG exhibits effective electromagnetic impedance matching and excellent microwave absorption properties. The minimum reflection loss reaches -43.7 dB at 12.5 GHz and the absorption bandwidth with reflection loss under-10 dB is in the range of 11.2-14.1 GHz when the thickness of composite is 1.2 mm. Furthermore, the ABS-based composite containing FeNi-FG presents better shielding effectiveness than that using original graphite as filler. (C) 2015 Elsevier B.V. All rights reserved.