Effect of sintering on the various properties of cobalt ferrite nanoparticles

Abstract

Cobalt ferrite nanoparticles with the structural formula CoFe2O4 were synthesized by the auto-combustion method to investigate structural and dielectric properties. The synthesized sample were calcined at 600°C at the heating rate of 5°C/min using the conventional heating. The calcined sample were taken in five equal proportions and then given conventional sintering at different temperatures of 700°C, 800°C, 900°C, 1000°C and 1100°C separately for 4 h at the same heating rate. X-ray diffraction spectra were obtained using Bruker D8 Advance X-ray Diffractometer and they confirmed the phase formation of all the samples. From the X-ray diffraction data, lattice constant, average crystallite size and theoretical density were calculated. The experimental density and porosity were also found out for all the samples. FTIR and dielectric properties such as dielectric constant, dielectric loss and impedance were studied. From the IR spectra, various metal-oxide bonds present in the samples were studied. The dielectric constant and dielectric loss were studied as a function of sintering temperature and frequency. Dispersive behaviour is observed for the variation of dielectric constant and dielectric loss with frequency. The dielectric constant was found to be increasing with the increase in sintering temperature in high frequency region. Possible mechanisms contributing to all the obtained results were being discussed.