Synthesis and Characterization of Nickel-Substituted Cobalt Ferrite Nanoparticles Using Sol–Gel Auto-combustion Method

In the present work, Co1−xNixFe2O4 (x = 0.02, 0.04, and 0.06 M) is prepared by sol–gel auto-combustion method and its structural, functional, magnetic, and morphological characteristics are analyzed. The peaks corresponding to the plane observed from XRD matches with JCPDS data of CoFe2O4 (22-1086) and NiFe2O4 (10-0325). It is noted that the average crystallite size decreases from 31 to 27 nm when the nickel concentration increases from 0.02 to 0.06 M, indicative of the incorporation of Ni2+ ion in the cobalt ferrite lattice. FTIR analysis shows the presence of M⇔\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\leftrightarrow $\end{document}O vibration at the tetrahedral and octahedral sites. Micro - Raman spectroscopy shows the stretching vibrations at 486.87 cm− 1 (Eg) and 696.96 cm− 1 (A1g), which are the characteristic vibrations of spinel ferrites. Magnetic studies show the variation in saturation magnetization (MS = 20.25, 9.41, 18.5 emu/g.) and coercivity (HC = 746.06, 953.03, 885.59 Oe) when the concentration of Ni2+ ion increases from 0.02 to 0.06 M. The prepared nanoparticles show a ferromagnetic nature which is attributed to the creation of an antiparallel spin and the magnetic moment created by the cation at tetrahedral and octahedral sites. The surface morphology of samples is imaged by a field emission scanning electron microscope.