Microstructure of Electrodeposited Co-Ni Alloy Films

Abstract

Co-Ni alloy films were potentiostatically deposited on a polycrystalline copper plate and a stainless steel plate from a sulfate bath. In the electrodeposited Co-Ni alloy, an α-phase formed in all compositions and an ε-phase coexisted from 0 to about 40 at% Ni. In the mixed α and ε phase, numerous stacking faults between the ε layers and the α layers occurred within one grain. Film grain size was affected by film composition independent of cathode potential and current density. Substrates crystallinity affected grain size and film surface morphology. Films on the polycrystalline copper plate grew epitaxially and showed a different morphology for the crystal face. Films on the stainless steel grew randomly and showed a ragged surface.