Tuning of magnetic properties and hyperfine interaction by the substitution of Ni2+ for cobalt ferrite nanoparticles

Abstract

The Co1−xNixFe2O4 (x = 0, 0.33, 0.5, 0.67, and 1) nanoparticles were prepared using a sol–gel method. The microstructure, morphology, magnetic properties, and hyperfine interaction were studied at room temperature. The X-ray diffraction patterns demonstrated the formation of spinel ferrite. The field emission scanning electron microscopy images denoted the translation of the nanoparticles from a spherical shape to a cube with increasing Ni2+ content, and energy dispersive X-ray analysis agreed with the implemented precursor and theoretically designed stoichiometry. The result of vibrating sample magnetometry denoted a monotonic decrease in coercivity and a nonlinear change in saturation magnetization with Ni2+ content. The cation distribution obtained from Mossbauer spectroscopy indicated the type of spinel ferrite transferred from mixed spinel to inverse spinel. The collinear magnetic order resulted in the sample with x = 0.67 exhibiting a high saturation magnetization (Ms = 66.4 emu/g) and coercivity (Hc = 602.4 Oe), making it a promising material for magnetic applications.