Influence of tetraethyl orthosilicate coating on dielectric, impedance, and modulus properties of barium hexaferrite nanoparticles prepared by a modified sol–gel method

This work is devoted to study the comparison of the conduction mechanism in bare barium hexaferrite (BaFe12O19) nanoparticles and tetraethyl orthosilicate-coated (SiO2)x/BaFe12O19 (x = 5, 10, 15 and 20 wt. %) nanoparticles. The modified sol–gel method was adopted for the synthesis of these nanoparticles. The structures, morphologies, elemental composition, vibrational modes, and dielectric properties of these nanoparticles were studied by x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and dielectric measurements, respectively. The crystallite size and particle size of BaFe12O19 nanoparticles decreased with SiO2 coatings, which can be attributed to the confinement of crystal growth of these nanoparticles with the coating. It was found that these (SiO2)x/BaFe12O19 nanoparticles have a uniform spherical shape, are non-agglomerated, and have a narrow particle size distribution. At room temperature, these (SiO2)x/BaFe12O19 nanoparticles showed distinctive behavior with varying frequency and SiO2 coatings. The experimental results in this work may provide fundamental support to the research and development of materials for energy storage devices.