Impact of Sm³⁺ and Er³⁺ Cations on the Structural, Optical, and Magnetic Traits of Spinel Cobalt Ferrite Nanoparticles: Comparison Investigation

Abstract

In this study, we investigated a comparison of the structure, morphology, optic, and magnetic (room temperature (RT)) features of Er3+ and Sm3+ codoped CoFe2O4 (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 (Sm3+ and Er3+ 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 Sm3+ and Er3+ 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.

Correlation between Cation Distribution and Magnetic and Dielectric Properties of Dy3+-Substituted Fe-Rich Cobalt Ferrite

“…Magnetic nanoparticles are known to exist in multimagnetic domain structures if the squareness ratio is greater than or equal to 0.5. For a sample with x = 0.000 to 0.075, the squareness ratio is less than 0.5, indicating that they are single-domain structures . Whereas the sample with x = 0.100 has a higher value of squareness ratio, meaning it has multimagnetic domains.…”

“…Rare-earth substitution (Gd 3+ , Dy 3+ , Er 3+ , etc.) in cobalt ferrite is extensively studied due to the highly interesting and tunable magnetic properties of the resulting materials. ,− However, for intrinsic and substituted/doped nanoferrites, the properties and performance characteristics are significantly affected by the particle size, size distribution, and cation distribution at A- and B-sites in the crystal structure. ,− Even a slight change in the method of synthesis and/or processing parameters along with precursor chemicals in the synthesis can result in variability in microstructure, crystal chemistry, and material properties. ,− For instance, Aziz et al showed comparisons of the properties of Dy 3+ -substituted cobalt ferrite between ultrasonication using ethanol and dry grinding, and the properties of magnetic materials changed . Thus, as evident from the literature, the degree of inversion depends on heat treatment, synthesis method, concentration, and nature of substituted ions. , …”

“…For a sample with x = 0.000 to 0.075, the squareness ratio is less than 0.5, indicating that they are singledomain structures. 27 Whereas the sample with x = 0.100 has a higher value of squareness ratio, meaning it has multimagnetic domains. For the sample with x = 0.050, the value of coercivity is 16.4 Oe, which is the minimum, and the sample with x = 0.100 has a maximum, which is 750 Oe.…”

Role of site selective substitution, magnetic parameter tuning, and self heating in magnetic hyperthermia application: Eu-doped magnetite nanoparticles

“…2,[9][10][11][12][13] Moreover, from the previous literature, Slimani et al reported the inuence of Sm 3+ and Er 3+ doping on the CoFe 2 O 4 system and found that saturation magnetization increases with an increase in doping concentrations. 14 Additionally, the anisotropydependent magnetic coercive eld is probably affected by the dopant concentration. However, when La 3+ and Y 3+ ions are both substituted in nano spinel ferrites, it will change the coercivity and magnetic anisotropy in an enhanced manner, as suggested by Almessiere et al 15 Among these, Eu-doped Fe 3 O 4 MNPs draw signicant attention, predominantly in clinical experimentations, due to the negligible toxicity of Eu 3+ and its unique magnetic and optical properties.…”

Magnetic properties, magnetocaloric effect, and critical behaviors in Co1−xCrxFe2O4

“…[11][12][13][14][15][16][17][18][19] The structural, magnetic, and MCE properties of COF can be tuned by doping/substituting divalent or trivalent cations. 11,[18][19][20][21][22][23][24] The tunability of structural parameters due to Cr 3+ substitution in stoichiometric and non-stoichiometric COF is reported in our earlier literature. 25 It was observed that there are structural defects due to Cr 3+ substitution.…”