Synthesis of CoFe2O4 powders with high surface area by solution combustion method: Effect of fuel content and cobalt precursor

Abstract

High surface area cobalt ferrite (CoFe2O4) powders were synthesized by solution combustion method. The dependence of the adiabatic temperature and the released gases during combustion reaction on the fuel content and cobalt precursor type, cobalt nitrate and cobalt acetate, was thermodynamically calculated. Thermal analysis, infrared spectroscopy, X-ray diffractometry, nitrogen adsorption–desorption, electron microscopy and vibrating sample magnetometer were used for investigation of the phase evolution, surface areas, morphology and magnetic properties of the synthesized CoFe2O4 powders. The specific surface area decreased from 285.4 to 35.7m2/g with increasing of fuel to oxidant molar ratio, ϕ, from 0.5 to 1.25 for the cobalt nitrate precursor, while the maximum surface area of 182.1m2/g was attained at ϕ=1 for the cobalt acetate precursor. The synthesized CoFe2O4 powders from the cobalt nitrate precursor exhibited the higher saturation magnetization and coercivity on account of the higher purity and crystallinity.