Influence of La3+-Co2+substitution on X-band microwave absorption properties of Ba0.5Sr0.5Fe12O19 nanoparticles with insight into quarter wavelength phenomenon

The presented study aims to tune the microwave absorption properties by varying the chemical composition of Ba0.5Sr0.5Fe12O19 nanoparticles with Co-La substitution via the synthesis route of the sol-gel citrate precursor method. X-ray diffractograms (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR) confirmed the formation of pure phase M-type hexagonal ferrite with varying lattice parameters. The permittivity measurements revealed increased dielectric losses, indicating good energy dissipation behavior. Enhancement of magnetic behavior resulted from the strengthened exchange interactions between lattice sites, leading to higher permeability values. Significant reflection losses were exhibited by our synthesized samples with a maximum reflection loss of-42.08 dB at 4.62 GHz for x = 0.35 at an experimental thickness of 3 mm. The dependence of reflection loss peaks on matching thickness was analyzed using calculated thickness profiles, revealing their close agreement with simulated thickness. The study highlighted the potential of synthesized samples for electromagnetic signature reduction, in both commercial and military applications.