Direct synthesis of Fe3O4 nanopowder by thermal decomposition of Fe–urea complex and its properties

An easy synthesis route of magnetite (Fe3O4) nanopowder is developed by using thermal decomposition of Fe–urea complex ([Fe(CON2H4)6](NO3)3). The formation of Fe3O4 is confirmed from X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements. The morphological properties and magnetic properties of the Fe3O4 are characterized by transmission electron microscopy (TEM) and magnetic measurements, respectively. By an increase in reaction temperature from 200 to 300 °C, the average crystallite size of the Fe3O4 nanopowder increases from 37 to 50 nm. Room temperature magnetization hysteresis curves show that the Fe3O4 nanopowder possesses ferrimagnetic characteristics. The saturation magnetization of the Fe3O4 nanopowder increases from 70.7 to 89.1 emu/g when the reaction temperature increases from 200 to 300 °C.

Research highlights▶ Thermal decomposition of [Fe(CON2H4)6](NO3)3 in a closed container can produce Fe3O4. ▶ CON2H4 play an important role in the Fe3O4 formation process. ▶ The synthesized Fe3O4 nanopowder possesses ferrimagnetic characteristics.