Synthesis of magnetite nanoparticles by thermal decomposition: Time, temperature, surfactant and solvent effects

Abstract

Monodispersed magnetite (Fe 3O 4) nanoparticles can be synthesized by thermal decomposition of iron(III) acetylacetonate, Fe(acac) 3. High saturation magnetization M S of the magnetite particles is extremely important to realize the full potential of magnetite materials in biomedical application. In this work, we have studied the different effects (time, temperature and surfactant) on structure and magnetic properties of Fe 3O 4 nanoparticles. The M S of the particles are enhanced after the synthesis at a higher reaction temperature and/or a longer reaction time. However, the increase in reaction temperature and/or reaction time resulted in particle size increase and the broadening of the particle size distribution. In this work, high M S value of the magnetite particles has been achieved through adopting surfactant or modification of solvent to overcome the temperature and time effects, while the smaller size particles with an acceptable size distribution has been maintained. Size and morphology of the particles were studied by TEM while magnetic properties of the particles were measured using VSM. The saturation magnetization M S of the particles can be increased at higher reaction temperature and/or longer reaction time, while narrow size distribution of the particles can be maintained either by the selective adsorption of oleic acid to the particle surface or by synthesizing them using solvent free thermal decomposition reaction. © 2008 World Scientific Publishing Company.