Structural properties of cobalt substituted barium hexaferrite nanoparticles prepared by a thermal treatment method

A series of M-type hexagonal ferrites with BaCo$_{x}$Fe$_{12-x}$O$_{19}$ (x = 2.0, 3.0) composition were synthesized using a simple heat treatment method. The aqueous solution, containing metal nitrates and polyvinyle pyrrolidone (PVP) as a capping agent was used to prepare M-type barium hexferrite nanoparticles. The prepared hexaferrite particles were calcined at microwave frequency (2.45 GHz, power 900W, 5 min) as well as at 650$^\circ$C temperature. The structural properties of the samples were investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). XRD pattern shows the pure M-phase. The particle size of the powder prepared by this method ranged from 20 nm to 27 nm. The thermal properties of the sample were investigated by thermogravimetric Analysis (TGA), which confirmed the thermal stability of the barium hexaferrite sample prepared by the heat treatment method.