Synthesis and Characterization of Nanoparticulate Crystallite Cobalt Ferrite for Permanent Magnet Applications

Nanoparticulate cobalt ferrite CoFe2O4 (COF) was successfully obtained at relatively low temperature by means of a facile chemical wet method, namely citrate auto-combustion. X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), Fourier Transform Infrared (FTIR), and Vibrating Sample Magnetometry (VSM) were carried out to study the structural and magnetic properties, respectively. The XRD results confirm the formation of single spinel phase of COF with an average lattice parameter (a) of 8.38 nm. XRD analysis revealed that the crystal size is about 43 nm, which is close to the particle sizes observed from TEM images (45.33 nm). The FTIR measurements between 400 and 4000 cm(-1) confirmed the intrinsic cation vibrations of the spinel structure of COF. The experimental results have been explained on the basis of size and surface effects of the nanodimensional crystal of COE The high coercivity of the prepared nanodimensional COF is the figure of merit for permanent magnets. Dielectric parameters and AC conductivity were measured as a function of temperature (300 800) K and frequency starting from 100 kHz up to 5 MHz. The conduction phenomenon was explained on the basis of the electron hopping model.