ピロリン酸イオン－グリシン混合配位子浴からのスズ－ニッケル合金電析に及ぼすピロリン酸イオンの影響

抄録

We investigated the effects of pyrophosphate ions on tin-nickel alloy deposition from pyrophosphate-glycine complex baths. The potential - current density curves for the alloy deposition were measured using a rotating-disk electrode system and the cathodic current for each metal deposition was evaluated quantitatively based on the polarization curves.
Pyrophosphate ions promoted the dissolution of both tin ions and nickel ions in the alloy baths. Addition of pyrophosphate ions, however, polarized the reduction potential for metal deposition in the baths containing either tin ions or nickel ions. On the other hand, the inhibition effect caused by addition of pyrophosphate ions was weakened greatly in the tin-nickel alloy deposition from the baths having mixed ligand complexes consisted of pyrophosphate ions and glycine, which might indicate that tin ions facilitated nickel deposition and nickel ions also did tin deposition.