Characterization of Core–Shell CaFe1.925Sm0.05Gd0.025O4 @ Polymer from Synthesis to Applications

Abstract A novel core/shell nanoferrite material has been developed for use in various potential applications. Rare-earth doped calcium-ferrite with the compositional formula $$\text{Ca}{\text{Fe}}_{1.925}{\text{Sm}}_{0.05}{\text{Gd}}_{0.025}{\text O}_4$$ CaFe1.925Sm0.05Gd0.025O4 was prepared as a core using the citrate auto-combustion method before being coated with PVA as a polymeric shell. High crystalline and single-phase orthorhombic nanoparticles are confirmed by XR-D (X-ray diffraction). An estimate has been made for the mean size of the crystal structures by analyzing the broadening of XR-D lines within a range of 20 nanometers. HR-TEM (high-resolution tunnelling electron microscope) micrographs also showed that the particles had an orthorhombic shape with well-defined boundaries. EDX (energy-dispersive X-ray) and FT-IR were used to investigate the elemental constitution and the molecular structure of samples. The dielectric properties were discussed in the basics of interfacial polarization and Koop`s model. The anti-ferromagnetic nature of the samples was identified by a VSM (vibrating sample magnetometer). The proposed composition was found to improve the electromagnetic absorption performance, which was confirmed with the measurements of optical parameters from the absorbance spectrum recorded by the UV–VIS–NIR spectroscope. The optical band-gap and Urbach energies of the synthesized samples have been investigated, in addition to the refractive index and the extinction coefficient. The Wemple-DiDomenico oscillator model was used to examine the dispersion energies.