One-step synthesis of hematite (α-Fe2O3) nano-particles by direct thermal-decomposition of maghemite

In this research work, alpha-Fe2O3 nano-particles were prepared by direct thermal-decomposition of gamma-Fe2O3. Precursor powders (gamma-Fe2O3) were synthesized by wet chemical method at room temperature and then, the precursors were subsequently calcined in air for 1 h at 500 degrees C. Samples were characterized by thermal gravimetric analysis (TGA). X-ray diffraction (XRD), energy dispersive spectra (EDS), infrared spectrum (IR) and transmission electron microscopy (TEM), respectively. The XRD, EDS, and IR results indicated that the synthesized alpha-Fe2O3 particles were pure. The TEM image showed that the alpha-Fe2O3 nano-particles were spherical and 18 +/- 2 nm in size. Magnetic properties have been detected by a vibrating sample magnetometer (VSM) at room temperature. The gamma-Fe2O3 and alpha-Fe2O3 nano-particles exhibited a super-paramagnetic and weak ferromagnetic behavior at room temperature, respectively. Using the present method, hematite nanoparticles can be produced without expensive organic solvent and complicated equipment (C) 2010 Elsevier B.V. All rights reserved.