The structures of the two-dimensional layers formed in the underpotential deposition of lead onto carefully prepared single crystals of copper are shown to depend upon the substrate orientation for (111), (100) and (110) surfaces. Nucleative growth processes are observed for first order and for higher order phase transitions. Comparison is made with the behaviour observed on silver substrates and the differences are ascribed to the change in atomic radius and in eletronegativity. Formation of the underpotential layer is shown to be a necessary precursor to overpotential deposition, the mechanism of which is markedly dependent on substrate orientation.

Neodymium was electrochemically deposited from NdF₃–LiF–Nd₂O₃ molten salt electrolyte onto the Mo electrode at temperatures close to 1273 K. Cyclic voltammetry and chronoamperometry measurements were the applied electrochemical methods. Metallic neodymium is obtained by potentiostatic deposition. The optical microscopy and XRD were used to analyze the electrolyte, the working electrode surface, and the deposit on the electrode. It was established that Nd(III) ions were reduced to Nd metals in two steps: Nd(III) + e⁻ → Nd(II) at potential ≈−0.55 V vs. W and Nd(II) + 2e⁻ → Nd(0) at ≈−0.83 V vs. W. Both of these processes are reversible and under mass transfer control. Upon deposition under the regime of relatively small deposition overpotential of −0.10 V to −0.20 V, and after the electrolyte was cooled off, Nd metal was observed at the surface of the Mo electrode. CO and CF₄ were gases registered as being evolved at the anode. CO and CF₄ evolution were observed in quantities below 600 ppm and 10 ppm, respectively.