Effect of deposition time on surface topography and electrical conductivity of carbon-nickel composite films

In this work, fractal dimensions and electrical conductivity of carbon–nickel films deposited at deposition times from 50 to 600 second were investigated. Because of the existence of fractal components in the surface topographies, the power spectra densities (PSDs) of all films show inverse power law variation at the high spatial frequency region. The fractal dimensions and the topography carbon-nickel films from 50 to 180 second are increased however; at 600 second these characteristics are decreased. It was observed that with increasing deposition time from 50 to 180 second, the room temperature electrical conductivity (σRT) of films increases from 2.87x10-9 to 2.3x10-8 Ω-1 cm-1 and then decreases to 6.62x10-9 Ω-1 cm-1 for films deposited at 600 second. Fractal dimensions and the room temperature electrical conductivity are in consistent with field emission scanning electronic microscopy (FESEM) images.