Impact of rare earth Ce³⁺ on the structural, and magneto-dielectric response of chemically derived Mg_0.5Zn_0.25Co_0.25Ce_yFe_2-yO₄ spinel ferrites

Spinel ferrites (SFs) have garnered significant interest due to their versatile properties and tunable structural, and magneto-dielectric properties. The SFs denoted as Mg_0.5Zn_0.25Co_0.25Ce_yFe_2-yO₄ (0.0 ≤ y ≤ 0.04), were prepared using the self-igniting method and investigated the structure, and magneto-dielectric behavior. XRD analysis verified the creation of a spinel matrix and a decrease in lattice constant (a) from 8.4629 Å to 8.3631 Å, while the crystallite size (D) of the as-prepared SFs increased with doping Ce³⁺ ions except y = 0.04. The coercivity ( \({H}_{C}\) $H_C$ ) and saturation magnetization ( \({M}_{S}\) $M_S$ ) was decreased from 1359.23 Oe to 543.01 Oe and 66.81 emu/g to 28.37 emu/g with the substitution of Ce³⁺ ions. Moreover, the microwave operating frequency was also reduced from 14.77 GHz to 6.27 GHz with the doping of Ce³⁺ ions. As the frequency increased, the dielectric constant ( \(\varepsilon^{\prime }\) ${\epsilon }^{\prime }$ ) and dielectric loss ( \(\varepsilon^{\prime \prime }\) ${\epsilon }^{″}$ ) as well as tangent loss (tan δ) decreased due to the influence of space-charge polarization, demonstrating a dispersive behavior at higher frequencies. Moreover, The \(\varepsilon^{\prime }\) ${\epsilon }^{\prime }$ , \(\varepsilon^{\prime \prime }\) ${\epsilon }^{″}$ and tan δ increased with the doping of Ce³⁺ in the MZCF lattice. Furthermore, the tuned magneto-dielectric properties of MZCCF SFs suggested that it is suitable for multifunctional applications.