Direct thermal decomposition synthesis and characterization of hematite (α-Fe2O3) nanoparticles

Hematite (alpha-Fe2O3) nanoparticles were prepared via direct thermal decomposition method using gamma-Fe2O3 as a wet chemically synthesized precursor. The precursor was calcinated in air at 500 degrees C. Samples were characterized by Thermogravimetric analysis (TGA), X-ray diffraction, Infrared, Scanning electron microscopy, Transmission electron microscopy (TEM) and Photon correlation spectroscopy (PCS). TEM and PCS analyses revealed that the average particle size of the alpha-Fe2O3 nanoparticles synthesized at 500 degrees C are about 18 +/- 2 nm and 50 +/- 3 nm for 1 h and 24 +/- 2 nm and 82 +/- 3 nm for 2 h, respectively. The difference in average particle size determined by PCS and TEM analysis is due to the electrostatic forces between particles, and their agglomeration in PCS analysis. Magnetic properties have been detected by a Vibrating sample magnetometry at room temperature. The alpha-Fe2O3 nanoparticles exhibited a weak ferromagnetic behavior at room temperature. (c) 2011 Published by Elsevier Ltd.