Investigating the Effect of Sintering Treatment on Structural and Magnetic Properties of Fe3O4 Nanoparticles

Abstract

The magnetite Fe3O4 nanoparticles with a size range of 8-9 nm were synthesis by the chemical coprecipitation of ferrous chloride, ferric chloride and NaOH as reducing agent with some modifications in the reported methods. The synthesized magnetic nanoparticles were heated at different temperature in the range of 250 °C to 850 °C. The effect of heating on structural properties of synthesized sample was studied by X-ray diffraction (XRD) and field effect scanning electron microscope (FESEM). The XRD patterns confirm the formation crystalline phase of Fe3O4 nanoparticles. The pattern formation of the nanoparticles was observed upon sintering treatment. Also there was a phase transition from magnetite (Fe3O4) to hematite (α-F2O3) was observed when the samples was heated above 550 °C. The vibrating sample magnetometer (VSM) was used to study the magnetic properties, hysteresis curve and the saturation magnetisation. The saturation magnetisation decreases as the annealing temperature increases which is attributed to the phase transformation.