Influence of ion implantation on growth mechanism of α-Fe₂O₃ nanowires/nanoblades

Hematite nanowires (NWs) and nanoblades (NBs) were successfully synthesized by thermal oxidation at 400 °C and 600 °C, respectively, under atmospheric conditions. Ion implantation was performed using a homemade metal vapor vacuum arc (MEVVA) technique as a new method to interfere with the growth mechanism of NWs/NBs. The metal, rare earth and gas ions with high energies were implanted into the NWs/NBs. The structure and morphology of NWs and NBs were systematically analyzed using different methods such as X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM). The NWs became short and bend, which showed a large deformation and the surface energy changed after Ni/Co/Er/Ar ion implantation. The implanted NWs/NBs were covered entirely by an oxide layer after a short annealing time and new NWs/NBs regrew during a long annealing time. The results were indicated that both the NW and NB formation mechanisms were ascribed to the tip growth model, where the diffusion played a key role. What’ more, the influence of ion implantation on growth mechanism of α-Fe₂O₃ NWs/NBs was independent of implanted ion species, implanted energy and dose and damage extent decided solely by defects.