Synthesis of magnetite nanoparticles via a solvent-free thermal decomposition route

Superparamagnetic nanoparticles have been widely applied in various bio-medical applications. To date, it is still a challenge to synthesize nanosized Fe3O4 particles with controlled size and distribution. In this paper, a novel solvent-free thermal decomposition method is reported for synthesizing Fe3O4 nanoparticles. Size and morphology of the nanoparticles are determined by TEM while the structure of the nanoparticles is identified by FTIR, XPS and TGA measurements. Magnetic properties of the obtained particles are determined using VSM and SQUID measurement. The particle size of the Fe3O4 can be tailored by adjusting either reaction temperature or time. When the reaction temperature is increased to 330 °C and the reaction time is extended to 4 h, the average particle size of the obtained nanoparticles is ∼9 nm, while Ms value reaches ∼76 emu/g. The as synthesized Fe3O4 nanoparticles show well-established superparamagnetic properties with the blocking temperature at around 100 K.