Nickel nanorods produced by annealing composite oxide films.

Nickel nanorods have been produced by annealing a dense composite film. The nanorods of 45-140 nm in lateral dimensions and 230-1400 nm in longitudinal dimensions were obtained by annealing NiO-YSZ composite films in H2 at 800 degrees C for one hour. The axis of the nanorods at the (220) direction was observed. The dense NiO-YSZ composite film was originally created by co-sputtering Ni and Zr-Y-Ce targets in Ar and O2 environment at 350 degrees C. Reduction of NiOx to Ni nuclei takes place on the surface of the film. The low crystallinity of the original composite film is believed to facilitate the NiO to grow into Ni nanorods on the discrete Ni seeds by diffusion.