Abstract:The effects of current density (J_k) and bath temperature on the structure of deposition layer of nickel and electrochemical noise energy (E^D) are studied, and the relationship between the structure of the deposit and E^D is also discussed in detail using electrochemical noise technique in coupled with the scanning electron microscopy and the glancing angle X-ray diffraction techniques. The results show that E^D theoretically mainly reflects the severity or rate of the local cathodic reaction rather than the integral cathodic reaction, and is markedly influenced by the electroplating current density (J_k)-depended nucleation/growth kinetics of the nickel deposit film. The proceeding of the nucleation (or the formation of new phase)/growth process of crystal nucleus on a foreign substrate possesses much more effect on E^D value than the subsequent homogenous growth of the already formed film particles, and the factors which can accelerate the drastic change of the electrode surface state should result in large E^D value.

Key words: nickel; electroplating; electrochemical noise energy; deposit structure