Enhanced magnetic properties of Dy³⁺ substituted Ni-Cu-Zn ferrite nanoparticles

Dy³⁺ substituted Ni-Cu-Zn (Ni0.4Cu0.4Zn0.2DyxFe2-xO4) ferrite nanoparticles were obtained at 600 °C by synthesizing sol-gel auto-combustion method, and they exhibit a particle size of 12–21 nm. X‐ray diffraction patterns confirm the presence of secondary phase of DyFeO3 and Fe2O3 for the Dy³⁺ substituted samples. Ni‐Cu‐Zn ferries doped with Dy³⁺ possess better grain structure and growth than that of pure Ni‐Cu‐Zn ferrite. The saturation magnetization increases remarkably up to 81 emu/g with increasing the Dy³⁺ ions. The increased saturation magnetization related to increased exchange interactions between Fe‐Fe ions and also with increased particle size. Blocking temperature was found to decrease with increasing Dy³⁺ substitution. An enhancement in initial permeability and Curie temperature was observed with Dy³⁺ substitution.