Preparation of Fe–B/Epoxy Composite Films by the LbL-Assisted Composite Plating Method Using Epoxy-Coated Fe–B Ultrafine Particles

Metal–insulator composite films, including Fe–B ultrafine particles and insulating epoxy films, were synthesized by the layer-by-layer (LbL)-assisted composite plating method. In this method, charged magnetic ultrafine particles were attracted to the cathode by electrostatic force simultaneously with the deposition of insulating epoxy thin film. To suppress the oxidation of Fe–B ultrafine particles in the reaction aqueous solution for Fe–B/epoxy composite film deposition, Fe–B ultrafine particles were coated with epoxy by using the electroless plating method. It was clear that epoxy coating on Fe–B ultrafine particles effectively prevents oxidation. The film deposited using epoxy-coated Fe–B ultrafine particles exhibited a smoother film surface than those obtained using uncoated Fe–B ultrafine particles. However, the highest amount of Fe–B content obtained in the deposited film was approximately 36 vol.% using Fe–B ultrafine particles with a concentration of 1.0 g/L.