Synthesis and characterization of single-crystalline α-Fe2O3 nanoleaves

By carefully controlling the reacting conditions, including atmosphere, temperature, and time, alpha-Fe2O3 nanoleaves have been synthesized by oxygenating pure iron. X-ray diffraction and transmission electronic microscope analyses demonstrate that the nanoleaves are single crystalline. The X-ray photoelectron spectrum, Raman spectrum. optical absorption spectrum, and photoluminescence spectrum are also carried out to characterize the nanoleaves. Magnetic measurement shows that the blocking temperature of the nanoleaves is about 120K and the coercivity decreases as temperature increases. The more interesting is that a small exchange bias is found in 2T field cooling hysteresis loops. This small exchange bias may possibly originate from a different magnetic order on the surface of the nanoleaves or the coexistence of a tiny amount of Fe3O4. (C) 2009 Elsevier B.V. All rights reserved.