Preparation and microwave absorption properties of Ni–B alloy-coated Fe3O4 particles

The Fe3O4 particles that were activated with Pd-Sn catalytic nuclei by single-step activation were used as cores for obtaining nickel- and boron-decorated particles with shell/core structure via electroless plating. The materials were characterized by TEM, SEM, EDX, X-ray diffraction, VSM and microwave network analyzer. The results showed that Fe3O4 particles coated with Ni–B alloy films had reduced metal deposition in the reaction solution. There was no peak of amorphous alloy Ni–B by XRD but the inverse spinal Fe3O4. The calculated results indicate that the Fe3O4 densely coated with Ni–B exhibits better absorption performance than the pure Fe3O4 in the range of 2–18 GHz, such as more powerful absorbing capability and a wider electromagnetic wave absorbing frequency band.