Monte Carlo study for the growth of alpha-Fe2O3 nanowires synthesized by thermal oxidation of iron

The growing mechanism of alpha-Fe2O3 nanowires synthesized by thermal oxidation of iron is studied by the Monte Carlo method. Using a model of diffusion, the effects of synthesizing temperature, oxygen density and annealing on the morphology of the nanowires have been simulated. The results show that nanowires with a large head can only be obtained under the correct temperature and a sufficiently high density of oxygen. Under a low temperature or a low density of oxygen, particles can be obtained. And under a high temperature or after annealing, the nanowires will become thicker. The results are consistent with our experiments. This fact indicates that the growth of alpha-Fe2O3 nanowires should be a diffusion process and provides an approach for improving the quality of the nanowires.