Fabrication of porous disk-like Ni/NiO microwave absorber and its excellent broad frequency absorption performance

This research reports a novel porous disk-like Ni/NiO binary composite with the diameter of disk ranged in 100-200 nm and the size of the porous distributed in 5-10 nm. The absence of Ni was generated by the partial reduction of NiO. This porous Ni/NiO product owns the matched impedance matching and attenuation electromagnetic wave ability since the moderate complexed permittivity and improved permeability value. In this regard, this composite proves to be desired electromagnetic absorber to treat the increasingly electromagnetic interference issue (EMI). The qualified absorption frequency bandwidth of the optimal Ni/NiO product covers 6.4 GHz (11.2-17.6 GHz) under the coating layer thickness of 1.5 mm. The excellent electromagnetic absorption properties have been discussed in depth. The unique porous structure benefits to the electromagnetic absorption performance which is due to the suppressed eddy current effect. (C) 2017 Published by Elsevier B.V.