Flexible PDMS-Ferrite Composite Sheets for EM Wave Absorption in the UHF Band

NiCuZnCo-ferrite was synthesized using the sol-gel combustion technique. Ferrite was put into a poly-dimethyl-siloxane (PDMS) polymer matrix at 25, 35, and 45 volume percent to create ferrite-polymer composites. X-ray diffraction (XRD) studies reveal that the ferrite has a cubic spinel structure and that the composite possesses both ferrite and polymer properties. According to thermogravimetric analysis (TGA), the PDMS-ferrite composite possesses thermal stability up to 380 °C. The morphology of the ferrite surface and the mixing of ferrite with the PDMS matrix were investigated using a field emission-scanning electron microscope (FE-SEM). The composites’ Young’s modulus increases as the ferrite loading content in the PDMS increases. The saturation magnetization value of the ferrite-PDMS composite is lower than that of the pure ferrite, according to the hysteresis curves; however, as the concentration of ferrite loading in PDMS increases, so does the saturation magnetization value. At room temperature, the dc electrical resistivity of the ferrite-PDMS samples is of the order of
$10^{12} \Omega $
cm. The samples’ complex permittivity and permeability spectra are analyzed throughout a frequency range of 1.0 MHz–3.0 GHz. The reflection loss (RL) of ferrite is −32 dB, whereas the RL of ferrite-PDMS composites is in the range of −25 to −15 dB. With increasing ferrite loading into PDMS, the value of RL increases, but the frequency of absorption falls from 3.0 to 1.8 GHz.