Impact of Sm 3+ and Er 3+ Cations on the Structural, Optical, and Magnetic Traits of Spinel Cobalt Ferrite Nanoparticles: Comparison Investigation.

In this study, we investigated a comparison of the structure, morphology, optic, and magnetic (room temperature (RT)) features of Er ³⁺ and Sm ³⁺ codoped CoFe ₂ O ₄ (CoErSm) nanospinel ferrite (NSFs) ( x ≤ 0.05) synthesized via hydrothermal (H-CoErSm NSFs) and sonochemical (S-CoErSm NSFs) approaches. The formation of all products via both synthesis methods has been validated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM), along with energy-dispersive X-ray (EDX) and transmission electron microscopy (TEM) techniques. The single phase of the spinel structure (except for the Hyd sample with x = 0.03) was evidenced by XRD analysis. The D _XRD (crystallite size) values of H-CoErSm and S-CoErSm NSFs are in the 10-14.7 and 10-16 nm ranges, respectively. TEM analysis presented the cubic morphology of all products. A UV-visible percent diffuse reflectance (DR %) study was performed on all products, and E _g (direct optical energy band gap) values varying in the 1.32-1.48 eV range were projected from the Tauc plots. The data of RT magnetization demonstrated that all prepared samples are ferromagnetic in nature. M - H data revealed that rising the contents of cosubstituent elements (Sm ³⁺ and Er ³⁺ ions) caused an increase in M _s (saturation magnetization) and H _c (coercive field) in comparison to pristine samples. Although concentration dependence is significant ( x > 0.02), no strict regularity (roughly fluctuating) has been ruled out in M _s values for doped samples prepared via the hydrothermal method. However, sonochemically prepared samples demonstrated that M _s values increase with increasing x up to x = 0.04 and then decrease with the further rise in cosubstituent Sm ³⁺ and Er ³⁺ ions. The calculated values of M _s and H _c were found to be greater in H-CoErSm NSFs compared to those in S-CoErSm NSFs. The present investigation established that the distribution of cations and the variation in crystallite/particle sizes are efficient to control the intrinsic properties of all samples.
Competing Interests: The authors declare no competing financial interest.
(© 2022 The Authors. Published by American Chemical Society.)