Investigation on the electromagnetic wave absorption properties of Ni chains synthesized by a facile solvothermal method

One-dimension Ni chains have been successfully prepared by a facile solvothermal method. The asprepared products were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA). The effects of the concentration of NaOH, solvent, reaction time on the morphologies of Ni samples were investigated. The experimental results showed that the volume ratios of ethylene glycol (EG) to water and the amounts of NaOH played critical roles in the formation of novel Ni chains. A probable formation mechanism of the chain-like Ni was proposed based on time-dependent experiments. The measured electromagnetic parameters showed that the absorption bandwidth with reflection loss (RL) less than -10 dB was up to 4.3 GHz in the high frequency range of 13.7-18.0 GHz by adjusting the thickness of 0.8-1.0 mm. A minimum RL value of -19.9 dB was observed at 17.2 GHz with a thickness of 0.8 mm. The excellent electromagnetic absorption mostly arises from dielectric loss rather than magnetic loss. (C) 2014 Elsevier B.V. All rights reserved.