Structural, magnetic, electrical, and Mössbauer study of Yb‑doped cobalt zinc ferrite nanoparticles

In this study, the effect of Yb on ­ Co0.5Zn0.5-xYbxFe₂O₄ (CZYFO) ferrites, with x ranging from 0.01 to 0.05, is synthesized, and the structural, magnetic, electrical, and Mössbauer properties are investigated through various characteristic techniques. CZYFO ferrites are synthesized through the citrate sol–gel auto-combustion method. X-ray diffraction patterns revealed a highly crystalline nature with a single-phase cubic spinel structure. The morphology of the prepared samples showed the loss of the porous gel structure upon Yb incorporation. EDAX confirmed the expected stoichiometric ratios of Co, Zn, Yb, and O. HR-TEM images indicated spherical nanoparticles with an average size of 28.2 nm. Optical band gaps, determined by UV-DRS and the Tauc method, ranged from 1.41 to 1.53 eV. Mössbauer spectroscopy indicated superparamagnetic behavior at room temperature. Vibrating sample magnetometer (VSM) measurements revealed weak ferromagnetic behavior, with the lowest saturation magnetization of 59.58 emu/g for X = 0.05. Arrott plots, based on Weiss molecular-field theory, supported the ferromagnetic contribution, showing good agreement between theoretical and experimental data. Dielectric studies showed a consistent decrease in both ε′ and ε″ with increasing frequency, aligning with the Maxwell–Wagner polarization model as described by Koop’s theory. Impedance measurements indicated relaxation phenomena and variations in bulk resistance. The Cole–Cole plot exhibited two semicircles, suggesting evidence for AC conductivity, while the values of μ′ and μ″ decreased significantly at lower frequencies. Overall, the CZYFO ferrites demonstrated enhanced dielectric properties, indicating potential for magnetoelectric applications due to their improved electromagnetic characteristics.