Preparation and Structure of FeNi Nanoparticles Coated with Ag and its Microwave-Absorption Properties

Microwave-absorption materials that have a good magnetic permeability and electrical conductivity are attracting more attentions in the EMI shielding field. This manuscript reported a kind of microwave-absorption FeNi@Ag nanoparticles fabricated through silver mirror reaction, i.e. silver was coated onto the surface of FeNi nanoparticles. The results showed that monodisperse spherical FeNi@Ag nanoparticles had been successfully prepared and exhibited ferromagnetic behavior with high saturation magnetization. Microwave-absorption performance suggested that the Ag coating onto the surface of FeNi nanoparticles could obviously improve the electromagnetic shielding ability of FeNi at 13–18 GHz, and the maximum reflection loss of FeNi@0.04Ag reached −36.6 dB.