CATALYTIC EFFECTS IN THE INITIATION OF AUTOCATALYTIC NICKEL DEPOSITION ON NICKEL-CONTAINING SUBSTRATES

Anodic stripping voltammograms of electroless nickel-phosphorus films showed two distinct peaks, which were attributed to the presence of two distinct solid phases. Partial anodic stripping, leaving the more noble material intact, yielded a phosphorus-rich surface. A quartz microbalance electrode was used to monitor the early stages of both open-circuit and fixed potential plating in a low temperature electroless nickel plating bath on this surface, as well as on normal electroless nickel-phosphorus and pure nickel films. The partially stripped film exhibited much higher plating rates, a phenomenon which is more readily explained in terms of enhanced catalytic activity rather than a simple surface area effect.