Investigation of the effect of fractional In3+ ion substitution on the structural, magnetic, and dielectric properties of Co-Cu ferrite

In3+-substituted Co0.9Cu0.1Fe2O4 with various small fractions of In3+ was prepared by the sol-gel auto-combustion method. The phase purity was verified by X-ray diffraction, the selected-area electron diffraction pattern, and Raman spectroscopy. The chemical composition was estimated and determined by inductively coupled plasma atomic emission spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The surface morphology and particle size of the compositions were analyzed by scanning electron microscopy and transmission electron microscopy, respectively. Mossbauer spectroscopy studies confirmed the ferrimagnetic nature of the material. Magnetic investigations were conducted at 300 and 5 K to determine the magnetic parameters. The saturation magnetization and coercivity were found to decrease on In3+ substitution. The Curie temperature showed a noticeable decrease with In3+ substitution because of dilution of magnetic interactions. Dielectric studies were performed with respect to frequency and temperature.