Study of Magnesium Ferrite/Polystyrene Composites for Microwave Absorption Applications

High-performance microwave-absorbing composites have attracted considerable attention in the field of electronic technology and telecommunications. These materials utilize stoichiometric combinations of components to enhance the magnetic parameters and reduce dielectric losses. In this work, microwave emulsion was used to synthesize magnetic nanocomposites with different concentrations of MgFe2O4 nanoparticles in polystyrene (PST). Samples of pure ferrite and PST were mixed in various amounts to form a ferrite polymer (FP-1, FP-2, FP-3, and FP-4, with 25%, 50%, 75%, and 100% ferrite, respectively). These composites were characterized using x-ray diffraction (XRD), dielectric characteristics, and vibrating-sample magnetometry (VSM). The XRD results showed that MgFe2O4 particles were evenly dispersed throughout single-phase PST. The crystallite size increased from 2 nm to 44 nm by mixing ferrites in PST. The dielectric properties were reduced as the percentage was decreased. The VSM tests indicated that all nanocomposites showed narrow loops and ferromagnetic behavior. The magnetic parameters decreased by adding the PST in magnesium ferrite components. The saturation magnetization decreased from 70 emu/g to 18 emu/g, remanence magnetization decreased from 21 emu/g to 5 emu/g, and coercivity decreased from 38 Oe to 8 Oe. All the above parameter results suggest that due to the high dielectric loss at high frequencies, magnesium spinel ferrites may be suitable for microwave absorption applications.