Structural, magnetic, and microwave absorption capabilities of Co2+ and Zr4+ doped Sr Ferrites for light-weight absorber applications

Electromagnetic pollution is a big challenge in today’s wireless technological environment. Microwave absorbers are designed to mitigate this problem. These are the materials that absorb electromagnetic radiation and mitigate its harmful effects on humans and electronic devices. Magnatoplumbite (M-type) hexaferrites with the molecular formula SrCo_yZr_yFe_12-2yO₁₉ were developed utilizing the sol–gel synthesis technique for microwave absorber applications. X-ray diffraction (XRD) was performed to investigate the structural purity of these synthesized hexaferrites. For the investigation on morphology, scanning electron microscopy (SEM) was done. An investigation on the magnetic characteristics was performed using different parameters like saturation magnetization (M_s), coercivity (H_c), remanence (M_r), and anisotropy field (H_a). There is a reduction in coercivity from 5011 to 2688 Oe, with a decrease in \({M}_{s}\) from 151.84 to 87.72 emu/g. From the absorption analysis, it was evident that the doping of Zr⁴⁺ and Co²⁺ has improved the absorption. A reflection loss (RL) of -41.70 dB for an 8.3 mm thickness and an input impedance (Z_in) of 383.25 Ω was achieved for composition SrCoZr 5 with a -10 dB absorption bandwidth of 504 MHz. With high absorption and low thickness, the prepared hexaferrites may be a promising candidate for defence and industrial applications as a microwave absorber.