Structural and magnetic properties of CoFe2O4 nanoparticles synthesized by starch-assisted sol-gel auto-combustion method in air, argon, nitrogen and vacuum atmospheres

Abstract

In the present work, structural and magnetic properties of CoFe2O4 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) (nu(1)) and around 340 cm(-1) (nu(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.