Preparation and Identification of BaFe2O4 Nanoparticles by the Sol–Gel Route and Investigation of Its Microwave Absorption Characteristics at Ku-Band Frequency Using Silicone Rubber Medium

In the last decade, spinel structures have been widely explored due to widespread applications in antibacterial nanocomposites, memory devices, catalysts, photocatalysts, high-frequency devices, and electromagnetic absorbing materials. In this study, BaFe2O4 spinel structures were synthesized through the sol–gel method using a low sintering temperature and were identified by vibrating sample magnetometer (VSM), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), and vector network analyzer (VNA) analysis. Results showed that uniform and pure crystal structures of BaFe2O4 nanoparticles were prepared based on the sol–gel method. Finally, BaFe2O4 nanoparticles were blended by silicone rubber to characterize the microwave absorption properties of the nanocomposite at the ku-band frequency. According to the VNA results, the BaFe2O4/silicone rubber nanocomposite with 1.75 mm thickness absorbed more than 94.38% of microwave irradiation along the ku-band frequency and the maximum reflection loss of the BaFe2O4/silicone rubber nanocomposite was 51.67 dB at 16.1 GHz.