Phase-controlled synthesis of nickel silicide nanostructures

Dense single-crystalline Ni2Si nanowires, Ni3Si2 nanowires and nanorods, and NiSi nanowires have been successfully synthesized in large-scale on the surface of Ni foam via a simple chemical vapor deposition of SiH4 at 450–600 °C. It is indicated that the reaction temperature and the flow rate of SiH4 play an important role in the control of phases and morphologies of nickel silicide nanostructures. The temperature controls the balance of Ni-diffusion and the degree of supersaturation of Si in Ni, thus producing different nickel silicide phases, whereas the different flow rates of SiH4 lead to the different nickel silicide morphologies by controlling the size and the quality of the nucleation centers. We expect that our synthesis approach and results will provide valuable information for the fabrication and application of other metal silicide nanostructures.