Structural, electrical, and magnetic studies on Er³⁺ doped cobalt-nickel based combusted nano ferrites

We produced Er³⁺ ion substituted Co_0.7Ni_0.3Er_xFe_2−xO₄ (CNE) ferrite series using the Sol-gel auto-combustion process. XRD confirms the Fd3m space group with cubic structure. Er³⁺ ions affect CNE ferrites’ crystalline size. Er³⁺ ion concentration increases crystal size (15.11 nm to 21 nm). Further, we have used a scanning electron microscopy (SEM) instrument to understand the morphology of prepared ferrites. Fourier transform infrared spectroscopy reveals presents minor Co₂ bonds; no other bonds existed. The vibrating sample magneto (VSM) meter provides essential information on our prepared ferrite’s magnetic properties. Replacement of Fe³⁺ ions by Er³⁺ ions at the octahedral location increases CNE series saturation magnetization. Er³⁺ ion substitution CNE systems had the greatest magnetic saturation and coercivity: 27.394 emu/g (x = 0.08) and 2074.74 Oe (x = 0.02). Using an LCR meter, we obtained the CNE sample’s real and imaginary dielectric constants with a change in frequency at room temperature. Dipole relaxation lowers the dielectric constant with frequency. This dispersion mimics ferrite conduction. All ferrites have a nearly constant dielectric constant at a given frequency. Debye relaxation theory may enhance CNE series features and dispersion with Er³⁺ ion replacement. All CNE samples improve AC conductivity with frequency. It could be explained by Maxwell-Wanger’s relaxation theory.