A comparative study of Nd and Sm doping on the structural, magnetic, and electromagnetic traits of Mg-Zn spinel nanoferrites

We present here the synthesis of Mg_0.5Zn_0.5R_xFe_2-xO₄ (x = 0.00, 0.05; R = Sm, Nd) spinel ferrite using the sol-gel auto-combustion (SGAC) scheme for examination of physical, electromagnetic, magnetic, and optical traits of Sm and Nd substituted Mg-Zn nanoferrites. The room temperature XRD patterns indicates cubic phase formation with the Fd3m space group. The size of crystallites goes from 29 to 19 nm by doping with Nd but, with the Sm doping, it decreases to 18 nm. FESEM pictures reveal the production of irregular grains with agglomerated morphology in all the undoped and doped nanoferrites. Based on a Fourier transform infrared study, it was shown that there were two distinct peaks at 525.55–529.41 cm⁻¹ and 416.75–418.09 cm⁻¹ representing the metal-oxygen bonds at octa and tetrahedral site locations, respectively. The M-H plots demonstrate a significant decline in the saturation magnetization with the neodymium and samarium substitution from 23.01 to 21.71 emu/g and to 11.63 emu/g, respectively. Low values of coercivity (10.03–58.82 Oe), retentivity (0.81–3.12 emu/g) and squareness ratio (0.037–0.268) confirms the superparamagnetic nature of prepared doped and undoped Mg-Zn nanoferrites and also suggests their potential use in solenoids and transformers applications. The electromagnetic examination of these Mg-Zn nanoferrites were reported within 1–10 GHz range, showing the high real permeability and permittivity with lower magnetic and dielectric losses. With the excellent electromagnetic characteristics, the prepared nanoferrites can be used as the substrate materials for antenna miniaturization application.