Nader Rezazadeh - Department of Chemistry Engineering, Islamic Azad University , Ahar, Iran.
Abbas Kianvash - Department of Materials Engineering, University of Tabriz, Tabriz, Iran.

In this research work, cobalt-ferrite (CoFe2O4) nanoparticles were synthesized by a simple, general sol-gel auto-combustion method. For this study, electromagnetic (EM) wave absorbing coatings with different weight fractions of nano-carbon and CoFe2O4 (which, arises from both dielectric and magnetic contributions) and polymeric epoxy resin were prepared and their characteristics were fully investigated. In this research, the physical properties of current products have been improved drastically. Values of reflection loss (RL) below -5dB can be obtained at the frequency range of 8-12 GHz for the composite with 1%wt nanocarbon and 59%wt CoFe2O4. As the weight fraction of nano-carbon in the composites is increased, the minimum reflection loss is reduced with a matching thickness of 1mm. This investigation concludes that hybrid EM absorbents in the form of paints, consisting of nano-sized CoFe2O4 and nano-carbon show excellent broad bandwidths of absorption. The structure, morphology and absorption properties are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vector network analyzer (VNA).

Radar wave absorption,Flexible wave absorber,Absorbing nanocompositesCoFe2O4 nanoparticles,Nanocarbon,,