Electrical resistivity of bulk nanocrystalline nickel

The effect of grain boundaries on the electrical resistivity of bulk nickel with a nanocrystalline structure has been investigated. For this study, nanocrystalline nickel was produced using a pulse plating technique that yields equiaxed nanostructures with negligible porosity. Using the four probe technique, resistivity measurements were performed at various temperatures ranging from 77 K to room temperature. The values of the resistivity were found to increase with decreasing grain size. This is mainly due to the increased volume fraction of interfaces at smaller grain sizes and the associated electron scattering events at the grain boundaries. The temperature coefficient of resistivity was found to decrease with decreasing grain size.