Synthesis and characterization of a large amount of branched Ni2Si nanowires

A large amount of Ni₂Si nanowires sheathed with amorphous silicon oxide has been generated from Ni substrates, for the first time, by thermal chemical vapor deposition using SiH₄ gas at 500 °C. The Ni₂Si nanowires obtained possess substantial amounts of branches (about 2-m length) grown on the main stems (about -–30 80nm diameter and -–10 20m length). High-resolution transmission electron microscopy and electron diffraction have revealed the orthorhombic Ni₂Si phase and the orientation. At the tail end along the branch grown on a stem an amorphous phase was also observed. The Raman spectrum was further used to characterize the product. A possible growth process of the branched Ni₂Si nanowires is briefly discussed. PACS 81.05.Bx; 81.07.Bc; 81.15.Gh; 87.64.Ee; 87.64.Je