Making the surface of nanocrystalline Ni on an Si substrate ultrasmooth by direct electrodeposition

Nanocrystalline (50-μm-thick) Ni films with controlled surface morphology at the nanoscale were synthesized by direct-current electrodeposition of Ni on an Si substrate under different electrochemical conditions. A relationship between spatial roughness scaling and mean grain size in electrodeposited Ni was established using X-ray diffraction and atomic force microscopy. Fractal analysis showed a transition from self-affine to ultrasmooth surfaces. A non-destructive method is demonstrated to estimate the grain size distribution of ultrasmooth nanocrystalline Ni surfaces by atomic force microscopy with high-resolution probes.