Sol–Gel Auto-combustion Preparation of M2+  = Mg2+, Mn2+, Cd2+ Substituted M0.25Ni0.15Cu0.25Co0.35Fe2O4 Ferrites and Their Characterizations

Cost-effective and controllable synthesis of M0.25Ni0.15Cu0.25Co0.35Fe2O4 (M2+  = Mg2+, Mn2+, and Cd2+) ferrites via the sol–gel auto-combustion technique. The impact of divalent cations on the structural, dielectric, and optoelectrical properties of ferrites was examined by XRD, FTIR, Raman, LCR, UV–Vis, and two probe I-V measurement techniques. The crystallite size was 52.66 nm, and the minimum specific surface area was observed 5.1507 m2/g for Mg2+ doped NCCF ferrite. The FTIR and Raman analysis also confirmed the substitution of divalent cations (M2+  = Mg2+, Mn2+, and Cd2+) at their respective lattice sites. The maximum energy bandgap was 1.67 eV Mg2+-doped NCCF ferrite as compared to other divalent ion-doped ferrites. The dielectric loss decreased while the ac conductivity increased with increasing frequency, and the minimum values were observed for Mg2+-doped NCCF ferrite. The activation energy was observed maximum for Mg2+-doped NCCF ferrite (0.2234 eV). Due to incredible properties including small specific surface area, large energy band gap, high resistivity, and loss dielectric loss of Mg2+-doped NCCF ferrite have potential applications in different fields.