A MODEL OF OXIDE LAYER GROWTH ON AG-IMPLANTED NICKEL ANODE IN AQUEOUSALKALINE-SOLUTION( AND PT+ ION)

This work investigates nickel oxide films growth on nickel implanted w ith ions of the noble metals Ag and Pt. Polycrystalline and single cry stal samples of Ni were implanted with high fluences (1 X 10(19)-1 X 1 0(21) m(-2)) of 9-50 keV ions. Galvanostatic and potentiostatic polari zation techniques were applied to monitor the electrochemical efficien cies of formation of NixO1-x films in aqueous KOH solution (30%) at 35 3 K. The growth rates, thickness and compositional profiles of oxidise d nickel layers were examined by means of RBS. It was found that the a nodic oxide film consists of Ni(OH)(2)XH2O (X greater than or equal to 1). Anodic oxidation of nickel occurs due to out-diffusion of Ni atom s through the hydroxide layer. Implanted Ag penetrates partly into the anodic oxide whereas platinum is completely buried beneath the oxide film. (C) 1997 Elsevier Science S.A.