Authors: Mohammad Mousavinia Ali Ghasemi Ebrahim Paimozd
Publish Date: 2014/04/07
Volume: 43, Issue: 7, Pages: 2573-2583
Abstract
Ni/Co/Snsubstituted strontium ferrite SrFe12−x Ni05Co05Sn x/2O19/multiwalled carbon nanotube MWCNT nanocomposites were produced by assembling ferrite particles on the external surfaces of MWCNTs Various techniques including xray diffraction XRD analysis transmission electron microscopy fieldemission scanning electron microscopy FESEM and Fouriertransform infrared FTIR spectroscopy were used to demonstrate the successful attachment of ferrite particles onto the external surfaces of the MWCNTs XRD analysis and FTIR spectroscopy confirmed the presence of strontium ferrite and carbon nanotube phases in ferrite and nanocomposite samples respectively FESEM micrographs indicated the formation of ferrite particles on the outer surfaces of MWCNTs in nanocomposite samples Furthermore vibratingsample magnetometer VSM and reflection loss RL measurements were performed to assess the magnetic and microwave characteristics of the synthesized samples VSM loops confirmed a relatively strong dependence of the saturation magnetization and coercivity on the volume percentage of MWCNTs With the introduction of MWCNTs or an increase in the substitution the saturation magnetization and coercivity were decreased The RL properties of the nanocomposites were investigated in the 8 GHz to 12 GHz frequency range The sample with 80 wt nanocomposite content showed a maximum RL of −35 dB at 83 GHz with a 4 GHz absorption bandwidth over the extended frequency range of 8 GHz to 12 GHz for absorber thickness of 18 mm The RL evaluations indicated that these nanocomposites have high potential for application as wideband electromagnetic wave absorbers at GHz frequencies
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