<p>Soft/soft (S/S) Co_0.5Ni_0.5Sc_0.04In_0.04Fe_1.92O₄@MFe₂O₄ (M = Mg, Cu, Zn, Mn) nanocomposites (NCs) were fabricated using a facile one-pot sol–gel approach. The soft/soft spinel ferrite structures were confirmed via XRD powder patterns and HR-TEM. with crystallite sizes within range of 25 to 31 nm being observed. It was observed that the lattice constants fluctuated with changing of the dopant in MFe₂O₄ (M = Mg, Cu, Zn, Mn). A study investigating the impact of various MFe₂O₄ (M = Mg, Cu, Zn, Mn) ratios on the electrical and dielectric features of these NCs indicated that the Mg-substituted NC exhibits moderate conductivity with the lowest activation energy (Ea), while the Mn-substituted sample demonstrates enhanced electron hopping and reduced impedance due to mixed ionic-electronic conduction. Zn substitution introduces higher Ea and complex impedance behaviour, suggesting increased lattice distortion. These findings highlight the influence of metal ion substitutions on the electrical and dielectric characteristics of the NCs, suggesting potential applications in electronic and magnetic devices depending on the desired property profile.</p> Graphical Abstract <p></p>