Structural, Cation Distribution, and Magnetic Properties of CoFe2O4 Spinel Ferrite Nanoparticles Synthesized Using a Starch-Assisted Sol–Gel Auto-Combustion Method

In this article, cobalt ferrite nanoparticles were synthesized using a starch-assisted sol–gel auto-combustion route. The significant role played by further annealing temperatures of 300, 500, 700, 900 and 1100 °C on particle size and magnetic properties of ferrite nanoparticles was explored and reported. The prepared nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, using a vibrating sample magnetometer. The X-ray diffraction patterns demonstrated singlephase formation of CoFe 2 O 4 spinel ferrite nanoparticles at different annealing temperatures. The FESEM analysis indicated a change of particle size and morphology at higher annealing temperature. The change in Raman modes and infrared absorption bands was observed with change of particle size and cation distribution. The highest value of coercivity (1091.2 Oe) and the saturation magnetization (54.76 erg g −1 ) were obtained at annealing temperatures of 900 and 1100 °C, respectively. X-ray photoelectron spectroscopy revealed the presence of Co 2+ and Fe 3+ at octahedral and tetrahedral sites in CoFe 2 O 4 nanoparticles. Further, the cation redistribution with change of particle size was confirmed by X-ray photoelectron spectroscopy.