Electrochemical formation of Yb-Ni alloy films at a Ni cathode was investigated in a molten LiCl-KCl-YbCl3 (0.5 mol%) at 723 K. A very thin YbNi2 film ( similar to 100 nm) was formed by potentiostatic electrolysis at 0.10 V (vs. Li+/Li) for 24 h. A much thicker YbNi2 alloy film ( similar to 7 mum) was formed by Li codeposition method (cathodic galvanostatic electrolysis at 50 mA cm(-2)) for 1 h. The formed YbNi2 films were changed to Yb2Ni17 and alpha-Ni phases by anodic potentiostatic electrolysis depending on the applied potentials. The formation potentials of Yb2Ni17 and YbNi2 were found to be 0.75 and 0.25 V, respectively. (C) 2003 Elsevier Science Ltd. All rights reserved.