Preparation and identification of bare and capped CuFe2O4 nanoparticles using organic template and investigation of the size, magnetism, and polarization on their microwave characteristics

Abstract The aim of this study was investigation of the size, magnetism, and polarization effects on the microwave absorption properties of the CuFe2O4 nanostructures. Firstly, two morphologies and magnetic properties of CuFe2O4 nanoparticles were prepared and identified using sucrose as a novel organic capping agent through the sol–gel method. The X-ray powder diffraction (XRD) analysis confirmed that bare and capped CuFe2O4 crystal structures were synthesized with a size of 15.6 nm given by Scherrer equation. Based on the field emission scanning electron microscopy (FE-SEM) micrographs, the capping agent enhanced size and agglomeration of the nanoparticles. The vibrating sample magnetometer (VSM) tests exhibited more isotropic property for the pristine nanoparticles governed by the Snoek’s law. The UV–Vis light absorptions and energy band gap spectra of both types of nanoparticles were studied by the diffuse reflection spectroscopy (DRS) analysis. The Fourier transform infrared (FT-IR) spectra indicated that all organic impurities were eliminated after heat treatments. Finally, the influence of the dipole and interfacial polarizations on the microwave absorption characteristics were revealed by vector network analyzer (VNA) using the silicone rubber or polyvinylidene fluoride (PVDF) as polymeric matrices. The obtained results indicated that the maximum reflection loss of the capped CuFe2O4/PVDF nanocomposite was -72.91 dB at 13.46 GHz and bare CuFe2O4/PVDF nanocomposite absorbed bandwidth of 8.27 GHz more than 10 dB in the x and ku-band frequency with 2 mm thickness. In this study, broadband, simple, superior, and affordable microwave absorbing nanocomposites were prepared using CuFe2O4 nanoparticles as one type filler. Interestingly, the organic capping agent declined surface area to volume ratio, magnetic isotropic property, and interfaces led to decrease microwave absorption bandwidth while PVDF due to reinforcement in dipole polarization improved bandwidth.