Abstract: In order to obtain IR absorption property, Ni-P was coated on barium ferrite powder by electroless plating, and the influence of electroless plating process on IR emissivity of barium ferrite powder was studied. The micrograph and structure of samples were studied by means of SEM and XRD. The IR and microwave absorption properties of powders were analyzed by FT-IR and Vector Network Analyzer. The optimal technology parameters are as follows，the concentration of NiSO₄ is 30g/L, the concentration of Na₃PO₃ is 20g/L, the concentration of sodium citrate is 70g/L, the concentration of (NH₄)₂SO₄ is 50g/L, reaction temperature is 85℃ and pH is 10.0. And the results show that a uniform and compact Ni-P coating is plated onto barium ferrite. The IR and microwave absorption properties of Ni-P coated barium ferrite are greatly improved. IR emissivity of the powder decreases to 0.5910 at 8－14 μm wavelength, and the maximum reflection is －24.3dB at 2－18GHz. The bandwidth (>10dB) is about 2.8GHz.

Key words: barium ferrite, electroless Ni-P plating, IR emissivity, microwave absorption properties