Effect of synthesis temperature on the characteristics of iron oxide magnetic nanoparticles

In this study, the magnetite (Fe3O4) nanoparticles were synthesized via chemical coprecipitation method. The effects of synthesis on the size and magnetic properties of them were investigated. The precipitation occurred by pH adjustment of ferrous/ferric mixed salt-solution with ammonium hydroxide addition. The synthesis was performed in the temperature range of 25°C to 80°C in ambient atmosphere. The magnetite nanoparticles were characterized by X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM) analysis. The crystallite size was calculated via reclaimed Sherrer formula. The results show that the magnetite is the major phase for all temperatures and both of the synthesis atmospheres. It was revealed that the temperature is effective for magnetic properties enhancement. A similar result was obtained for magnetite phase formation. The saturation magnetization was obtained 31emu/g to 66 emu/g. It was found that the superparamagnetic property of nanoparticles is reduced by synthesis temperature.