A study of electroless displacement of cobalt by copper during the electrochemical preparation of Cu–Co alloy multilayers by pulse polarization

The cobalt electroless displacement by copper during the electrochemical deposition of Cu–Co multilayers has been investigated. A chrono-potentiometric technique, atomic absorption and quartz microbalance have been used to carry out the investigations. The pH value considerably modifies the kinetics of the chemical displacement reaction. High pH values contribute to the formation of Cu2O. The electroless displacement is plainly diffusion controlled during the first instants. The analysis of Cu–Co multilayers realized by pulse polarization highlights that the displacement may be negligible for a 100 nm layer but may represent half the whole layer for a thickness of approximately 1 nm.