  We report a study on the growth of NiBi3 nanowires and nanorods during the
preparation of superconducting NiBi3 films by co-evaporation of Ni and Bi. We
find that NiBi3 films grown via co-evaporation of Ni and Bi metals achieve
higher transition temperatures (4.4 K) compared even to the single crystal
NiBi3. However, in certain parameter space, the film surfaces were spattered
with nanoscale features, such as nanowires and nanorods. Ambient temperature
deposition resulted in polycrystalline NiBi3 nanorods which were controllable
with the evaporation rate of Bi. Deposition at elevated temperatures promoted
the emergence of long single crystalline NiBi3 nanorods. High resolution
transmission electron microscopy measurements confirmed the crystalline
behaviour of the nanorods. We believe that NiBi3 nanowires form in a process
analogous to the well known vapor-liquid-solid process, as we observe an
amorphous Bi cap on the nanorods. From glancing angle X-ray diffraction
measurements we identify that the presence of trigonal Bi with hexagonal
primitive cell in the film promotes the nucleation of nanorods. Electrical
transport on a single NiBi3 nanowire shows a superconducting transition of
4.3K.
