To lg PdC12 we added 1 ml concentrated HC1 and I0 mI H20. After complete dissolution we diluted 1 ml of the above in 50 ml of H~O. This was the stock solution. Any of the following 3 activators work equally well. They differ only in the ensuing deposition rate. deposition rate of No. 1 < deposition rate of No. 2 < deposition rate of No. 3 Activator bath No. 1:5 ml stock + 95 ml H20 Activator bath No. 2:10 ml stock + 90 ml H20 Activator bath No. 3:15 ml stock 4-85 ml H20.

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Differential capacitance measurements have been used to study mosaic lithiated nickel oxide electrodes and to obtain information concerning the potential distribution between the space charge region within the semiconductor and the Helmholtz layer in the electrolyte. Plots of 1/C 2 vs. E have been found to exhibit linear behavior over substantial ranges of potentials in accord with the Mott‐Schottky treatment. The slopes are somewhat higher than expected from the Li content although they approach the Mott‐Schottky values for electrodes prepared with shorter Li doping times. At potentials anodic to 1.0V‐0.059false(pHfalse)VnormalreSHE the change in electrode potential appears principally across the Helmholtz plane.

High-quality specimens of sufficient thickness for reliable testing are needed if the enhanced properties observed for ultrastructured multilayered metals are to be understood and exploited. In the present paper, factors affecting the quality of multilayers electrodeposited from a single electrolyte, via concerted modulation of the electrode potential and electrolyte mass transport, are discussed. The importance of precise control of the potential during deposition of the more noble metal is emphasized. Results obtained by a pulse technique show that Ni passivation does not occur under the conditions used to electrodeposit Ni-Cu multilayers. Attainable deposit quality is illustrated by tensile test data for a series of 90%Ni-10%Cu specimens that are twice as strong as Ni and for which the standard deviations for the ultimate tensile strength and modulus are only 1.5 and 3.9%, respectively.

A new voltammetric stripping method for determining the concentration of brightening or leveling additives in plating baths is described. The method is based on the effect that such additives exert on the rate of metal electrodeposition. To determine the latter, the potential of an inert rotating electrode is cycled in the bath, so that a small amount of metal is alternately deposited on the surface and then stripped off, i.e., anodically dissolved. The charge required to strip the copper is related to the deposition rate and, thus, to the concentration of additive in the plating bath. Errors caused by changes in the electrode surface or bath composition are mitigated by using the internal standard provided by the static electrode. Results are reported for the determination of both 2,5-dimercapto-l,3,4-thiadiazole and proprietary brightener PY61-H in copper pyrophosphate baths, for which a precision of about 0.1 ppm (0.1 ml/liter of PY61-H) was attained in the concentration range from 0.0 to 2.5 ppm (0.0-2.0 ml/liter). The effect of bath contamination is also considered and a model is proposed to explain the effectiveness of dimercaptothiadiazoles as leveling agents.