Synthesis and Microstructures of α-Fe 2 O 3 Bicrystalline Nanowires

Novel Fe2O3 nanowires have been successfully synthesized by a simple oxidation process of pure iron. The microstructure of the Fe2O3 nanowires have been systematically investigated by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM). The investigated materials are found to be stoichiometric rhombohedral α-Fe2O3 with typical diameters of 20–80 nm and lengths up to 20µm. In addition to known single crystal Fe2O3 nanowires, a great amount of novel bicrystalline nanowires were found with ellipsoidal heads. Investigations indicate that most of the bicrystalline nanowires are twins and their orientation relationship is obtained to be (−1,1,10)M//(-1,1,10)T, [110]M//[−1−10]T. High resolution TEM with numerical reconstruction of the electron exit wave was used to investigated the atomic structure of the micro-twins. Their growth mechanism is briefly discussed on the basis of solid phase growth process.