Fine tuning of CoFe2O4 properties prepared by solution combustion synthesis

Single phase CoFe2O4 powders were prepared by solution combustion synthesis using β-alanine as fuel. By adding to the reaction mixture various amounts of oxalic acid, which act as a retarding agent and pore generator, properties of CoFe2O4 powders can be properly adjusted. Depending on the amount of oxalic acid, the average crystallite size of CoFe2O4 ranges between 13 and 41 nm, whilst the specific surface area varies between 1.8 and 34.4 m2/g. The combustion synthesized CoFe2O4 powders exhibit a hard ferimagnetic behavior. The CoFe2O4 coercivity varies between 71.8 and 126.0 kA/m and the saturation magnetization ranges between 53.0 and 70.6 emu/g. After uniaxial pressing and sintering at 1400 °C for 4 h, the pellets reached relative densities up to 90% of the CoFe2O4 theoretical density.