Structural and Magnetic Properties of CoFe2O4 Nanoparticles Synthesized by Starch-Assisted Sol–Gel Auto-Combustion Method in Air, Argon, Nitrogen and Vacuum Atmospheres

In the present work, structural and magnetic properties of CoFe 2 O 4 nanoparticles synthesized by starch-assisted sol–gel auto-combustion method in air, argon, nitrogen and vacuum atmospheres were investigated. The particle size, shape, crystal structure and magnetic properties of synthesized ferrite nanoparticles were investigated by powder X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM), Raman spectrometer, Fourier transform infrared spectroscopy (FTIR) and a vibrating sample magnetometer (VSM). The FE-SEM micrographs indicate the octahedron-like cobalt ferrite nanoparticles formation in air atmosphere; however, spherical nanoparticles were formed in argon, nitrogen and vacuum atmospheres. An infrared spectroscopy study showed the presence of two absorption bands in the frequency range around 560 cm −1 ( ν 1 ) and around 340 cm −1 ( ν 2 ) which indicated the presence of tetrahedral and octahedral group complexes, respectively, within the spinel lattice. Room temperature magnetization measurements showed that the saturation magnetization ( M s ) and coercivity ( H c ) were influenced by cobalt ferrite formation atmosphere, i.e., air, argon, nitrogen and vacuum.