The densification and the fractal dimensions of carbon–nickel films annealed at different temperatures 300, 500, 800, and 1000∘C with emphasis on porosity evaluation are investigated. For this purpose, the refractive index of films is determined from transmittance spectra. Three different regimes are identified, 𝑇 < 500∘C, 500∘C< 𝑇 < 800∘C and 𝑇 > 800∘C. The Rutherford backscattering spectra show that with increasing the annealing temperature, the concentration of nickel atoms into films decreases. It is shown that the effect of annealing temperatures for increasing films densification at 𝑇 < 500∘C and 𝑇 > 800∘C is greater than the effect of nickel concentrations. It is observed that the effect of decreasing nickel atoms into films at 500∘C< 𝑇 < 800∘C strongly causes improving porosity and decreasing densification. The fractal dimensions of carbon–nickel films annealed from 300 to 500∘𝐶 are increased, while from 500 to 1000∘C these characteristics are decreased. It can be seen that at 800∘C, films have maximum values of porosity and roughness.
