Structural, magnetic, and electrical properties of sol-gel derived cobalt ferrite nanoparticles

Abstract : This work reports the synthesis and studies of semi-soft ferrimagnetic CoFe 2 O 4 nanoparticles using sol-gel method. The X-ray diffraction patterns confirm the formation of cubic spinel CoFe 2 O 4 nanoparticles. The average crystallite size was found from XRD data is about 30 nm. The high resolution transmission electron microscopy analysis shows that nanoparticles are highly crystalline. The magnetic properties reveal that the particles are ferrimagnetically ordered soft magnetic materials with coercive field of 620 Oe and saturation magnetization M s = 60 emug − 1. The higher value of saturation magnetization is due to the ordered single-domains magnetic nanoparticles and lower magnitude of coercivity is attributed to the decrease of inter-particle interactions and magneto-elastic anisotropy. The value of remanence ratio R < 0.5 is responsible for magnetostatic interactions of the particles. The nanoparticles possess low values of dielectric constant which decreased with increasing frequency. The low dielectric constant makes the nanoparticles as a promising candidate for high frequency magnetic devices.