Effects of anion species and the pH of Ni salt solution on the microstructure and electric resistivity of an Ni film prepared by an electroless plating method were examined by SEM, XRD, Hg porosimetory, BET surface analyses and resistometory.
Because they were made up of uniform microparticles, Ni films prepared from NiSO4
solutions gave the largest specific surface area, the lowest pore radius and the lowest specific resistivity, while those prepared from NiCl2
did not give good results due to the fact that their Ni particles were segregated and large, and had low crystallinity.
Ni films prepared from a pH 5 solution of NiSO4
gave the largest specific surface area and the lowest specific resistivity, owing to the uniformly grown Ni particles.
Ni films prepared from NiSO4
at pH 5 were thought to be the most suitable material for electrodes.