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 $$\text{Ca}{\text{Fe}}_{1.925}{\text{Sm}}_{0.05}{\text{Gd}}_{0.025}{\text O}_4$$ CaFe 1.925 Sm 0.05 Gd 0.025 O 4 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.

Reduced A–B super exchange interaction in zirconium doped cobalt ferrite due to laser irradiation

“…The magnetic hysteresis (MH) loop was conducted at room temperature (RT) for both non-radiated and irradiated samples, as shown in figure 7. The coupling among Fe 3+ (3d 5 ) and Fe 2+ (3d 6 ) unpaired electrons in their spin states via the O −2 ions' p orbitals gives rise to a ferromagnetic alignment [48,49]. All samples exhibited similar hysteresis curves with varying heights and widths, indicating that magnetization becomes saturated when a field of 15 kOe is applied for non-radiated samples.…”

Designing bi-functional Ag-CoGd0.025Er0.05Fe1.925O4 nanoarchitecture via green method

“…Larger ionic radii of RE ions compared to Fe ions imply greater strain, which changed the magnetic and electrical properties. Additionally, the interaction of the unpaired electrons in the 4f subshell of RE ions with the 3d subshell of Fe ions turns out the physical properties of the studied samples [15].…”

Comparative study of the structural, magnetic and electrical properties of cuprous delafossites CuBO2(B = Zn, Mn and Er) prepared using the flash auto-combustion technique

“…Several exchange mechanisms, such as direct and super exchange interaction, Ruderman-Kittel-Kasuya-Yosida (RKKY), and Stoner-magnetism mechanisms, which are well-established in conventional 3D bulk magnets, are also present in various 2D magnets [24,25]. Additionally, in 2D magnetic structures, there have been recent discoveries of notable exchange mechanisms, namely super exchange and multi-intermediate double exchange [26].…”