Based on the sol-gel combustion method, stoichiometric Fe 3? , Mn 2? , Ni 2? ions and citric acid were chosen as the initial reactants for the preparation of magnetic particles. Due to the different reduction ability of metal ions, completely different magnetic products (MnFe 2 O 4 oxide and FeNi alloy) were obtained by heating the flakes at 600°C under nitrogen atmosphere. MnFe 2 O 4 particles exhibit superparamagnetic behavior at room temperature, and martensitic phase transformation is observed magnetically at 125 K for FeNi alloy particles.