It was found by the measurements of IR, VR, and UV spectra and the electric conductance of Ni (CF₃COO)₂-halide-MeOH solution that the coordination of halide with Ni²⁺ ion was in a molar ratio of 1:2 in the solution. When an amount of Ni(CF₃COO)₂ beyond the coordination value mentioned above was added to the Ni(CF₃COO)₂-MeOH solution containing an ammonium halide, the electric conductance of the solution decreased. The strength of coordinate bond between Ni(CF₃COO)₂ and an ammonium halide seemed to be greater than that between Ni(CF₃COO)₂ and any of other halides.

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The application of electroless nickel plating on the sintered substrate of PbTiO₃-PbZrO₃ was studied as an available means for manufacturing precision electronic parts. An improvement in pretreatment process for such a lead-containing substrate was carried out. By trying an intermediate treatment of thin electroless plating of a noble metal between the conventional pretreatment and the electroless nickel plating, the electroless deposition of nickel was accelerated in its initial stage and uniformity of the deposited nickel film was also obtained. Among various factors affecting the deposition rate, the effect of sodium hypophosphite concentration was found to be greater than that of nickel ion concentration in the plating bath. The optimum plating conditions obtained were as follows: pH: 5.40, temperature: 80°C, and immersion time: 45min. Furthermore, the distributions of nickel and phosphor contents on the cross-section of the deposited film were examined by X-ray microanalysis. The phosphor content was lower in the layer nearer to the substrate in the initial stage of deposition, but it became higher nearer to the surface of deposit with the time of immersion; while, the nickel content was constant over the whole thickness of cross-section.

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Anodizing aluminum in a mixture of maleic acid-sulfuric acid at constant current densities frequently causes pittings in the coatings. However, the initial two-step current control, under which the current density was first raised to 0.5A./dm² in 1 minute, kept at the current density for another 1 minute and finally raised to the specified range of 1 to 3A/dm² in 1 minute, was able to prevent pittings and coatings of uniform thickness and color were obtained. This is interpreted that at the low current densities, the structual change from initial barrier layer to porous layer takes place through the slow dissolution of the barrier layer. Thus by anodizing aluminum for 30 minutes in a mixture containing 250g/l maleic acid and 3.0 to 6.0g/l H₂SO₄, colored coatings of various tones from light yellow to dark brown were obtained and they did not contain any defects. Colors of the coatings so obtained were found to correspond to the content of SO₄^2- incorporated into the films. The more the amount of SO₄^2- increased, the lighter the color of coatings decreased.

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The exoelectron emission from abrasive particles embedded in copper surfaces after abrasion with emery papers was measured using a gas-flow type G-M counter. The emission intensity was found to decrease with time at room temperature approximately according to the logarithmic decay law, but the emission was scarcely decayed at the liquid nitrogen temperature. Initial emission counts for first 10 minutes increased with increasing in the size of abrasive particles of emery paper. There were three marked peaks in the TSEE glow curve; at around 80°, 220° and 350°C. The peaks shifted with the time of storing in air after abrasion. Integrated total emission counts of the glow curve considerably decreased with the time of storing in air after abrasion. As the linear relationship was obtained between initial emission counts for first 5 minutes and integrated total emission counts of the glow curve from room temperature to 250°C, integrated total emission counts on heating were able to be estimated from the measurement of initial emission counts at room temperature. Initial emission counts varied between copper samples. The measurement of the exoelectron emission at room temperature is considered to be a simple and convenient method to evaluate properties of abraded metal surfaces.

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