Investigation on Phase Evolution in the Processing of Nano-Crystalline Cobalt Ferrite by Solid-State Reaction Route

Abstract

Cobalt ferrite nanocrystalline powder was synthesized from the powder mixture of cobalt carbonate and iron oxide by mixed oxide ceramic method. The effects of temperature of calcination as well as molar ratio of CoCO3/Fe2O3on the phase structure, morphology and magnetic properties of the products were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) techniques, respectively. The samples calcined at 800 and 900 C consisted of cobalt ferrite, iron oxide and cobalt oxide. In the sample calcined at 1000 C, the reaction was completed and single phase CoFe2O4with a mean crystallite and particle sizes of 49 and 300 nm, respectively was obtained. The above sample showed hard magnetic behavior with a coercivity of 337 Oe, saturation magnetization of 76 emu/g and remanence of 19 emu/g.