Microwave-assisted synthesis and magnetic property of magnetite and hematite nanoparticles

Nanoparticles of magnetite (Fe3O4) and hematite (alpha-Fe2O3) have been prepared by a simple microwave heating method using FeCl3, polyethylene glycol and N2H4 center dot H2O. The amount of N2H4 center dot H2O has an effect on the final phase of Fe3O4. The morphology of alpha-Fe2O3 was affected by the heating method. Crystalline alpha-Fe2O3 agglomerates were formed immediately at room temperature and most of these nanoparticles within agglomerates show the same orientation along [110] direction. After microwave heating, ellipsoidal alpha-Fe2O3 nanoparticles were formed following an oriented attachment mechanism. Both Fe3O4 and alpha-Fe2O3 nanoparticles exhibit a small hysteresis loop at room temperature.