Electroless plating preparation and microwave electromagnetic properties of Ni-coated carbonyl iron particle/epoxy coatings

The morphology, composition, electromagnetic and microwave absorbing properties of the electroless Ni plated carbonyl iron (CI) particles were characterized using electron scanning microscope (SEM), energy dispersive spectrometer (EDS) and microwave network analyzer. The SEM and EDS results indicate that the CI particles were coated with uniform Ni coating. After the CI particles were coated with Ni, the real part of complex permittivity of the Ni-coated CI particles decreased while the complex permeability and the imaginary part of complex permittivity kept almost constant. The complex permittivity and complex permeability of the Ni-coated CI particles filled epoxy coatings increased with increase in weight content of Ni-coated CI particles. Compared with the raw CI particles/epoxy coatings with the same coating thickness and particles content, the Ni-coated CI particles/epoxy coatings possessed higher microwave absorption in the X-band and the microwave absorbing peak shifted to a higher frequency range.