We studied sodium and ammonium gold sulfites as gold salt in a 45°C bath, and compared hardness. Conventional sodium gold sulfite bath deposits have a Vickers hardness of about 110Hv at 45°C. Deposits in an ammonium gold sulfite bath containing 200g/L of ammonium sulfite monohydrate had a Vickers hardness of about 90Hv at the same bath temperature. Ammonium gold sulfite bath deposits had a fully bright appearance free of metallic additives.
A plasma source ion implanter (PSII) has been built and used to study nitrogen ion implantation into silicon wafers and titanium substrates. Plasma was generated by rf (13.56MHz) glow discharge. A-20kV pulse bias voltage was applied to the substrate holder for 50μs at a repetition rate of 100Hz and for 10μs at a repetition rate of 500Hz. The substrate bias voltage and current during implantation were monitored using a voltage divider and current transformer. The substrate surface was analyzed using Auger electron spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Results showed that the PSII achieved uniform ion implantation into a three-dimensional substrate and that the Ti substrate surface was changed to TiN by nitrogen PSII treatment.
We studied the relationship between the properties and brightness of ZnS: TbFx phosphor films synthesized under different sputtering conditions. We clarified that the F/Tb ratio in films, ZnS (111) lattice plane distance (d), and the half width of the ZnS (111) peak profile (Δ2θ) markedly influenced emission brightness. These properties were varied with sputtering conditions such as RF power, sputtering gas pressure, substrate and annealing temperatures. We found the optimum conditions for synthesizing a brighter green ZnS: TbFx phosphor film to be 125W RF power, 1.33Pa sputtering gas pressure, 200°Csubstrate temperature and 300°Cannealing temperature.
Surfactants greatly influence degreasing velocity. To explain the differences due to surfactant type, we analyzed the remaining oil film thickness (T) and the emulsion characteristics induced by the surfactants involved It became clear that T had a strong relationship to the average oil globule diameter r∞ in the oil emulsion, which had been formed at a low concentration. T and (dT/dt)are summarized as follows: T=r∞/R, dT/dt(initial)=-C1*ra(T-r∞)/√r∞, dT/dt(end)=-C2*√r∞. R: Water wetting area ratio, ra: Substantial oil globule diameter of highly concentrated emulsion in boundary film. The degreasing velocity (dT/dt) in all surfactants was decided by ra and r∞ size. These sizes characteristically depended on the surfactant type and oil concentration. The ideal surfactant for high-speed degreasing, should therefore form an oil globule distribution at the smallest size<0.1 and r∞=2, ra>30μm. Little possibility existed; however, that (dT/dt) was controllable by using the specific globule size alone, which had the slowest movement velocity, only when degreasing by the surfactant ABS, etc., had nearly been completed.
We sputter-deposited oxide thin films such as Y2O3, SiO2, TiO2, Ta2O5, CeO2, and MoO3 and studied water droplet wettability and the surface friction coefficient under the controlled conditions of 20-25°C and 50-60% RH. Water droplet wettability was evaluated by measuring the contact angle. We found that the angle increased and saturated over time for all tested oxide thin films and that contact angle saturation depended on the type of oxide thin films used. The relationship between the contact angle and r/Z (ion radius divided by cation charge) suggests that the oxide surface structure affects adsorption states. We also found that the thin film surface friction coefficient also decreased over time in line with variations in the contact angle. The correspondence between the friction coefficient and adhesion derived from the contact angle means that friction originates in adhesive force.
Co-based films were deposited electrolessly on rapid-quenched Ni-based amorphous alloy ribbons. Electroless deposition is possible autocatalytically on amorphous substrates when dimethylamine borane (DMAB) is used as the regand agent. A Co-based alloy film with a maximum Fe content of 60at% was obtained by controlling chemical composition in the bath and deposition conditions. Magnetic properties of obtained films depended on surface conditions and the ribbon substrate composition. Changes in film layer structural and magnetic properties with different film thicknesses were observed when bimetals were heat-treated at a range of temperatures that did not crystallize the ribbon.
I2 concentration in a potassium iodide silver plating solution increases with time in the lower pH range. Which decreases cathode current efficiency in silver deposition, making it necessary to control pH between 4.5 and 5.0. Silver deposits become less adhesive with increasing pH. We studied the effects of pH near electrode surfaces on silver deposit adhesion. We found the following: (1) The pH value near the cathode surface was much greater than that of bulk solution during electrodeposition without a buffer. The addition of KH2PO4 as a buffer markedly reduced the pH change near the electrode. (2) Silver deposit adhesion to undercoated nickel surfaces was improved by adding KH2PO4.
Electrolyte anions and water are incorporated in anodic alumina films during aluminum anodization. Component distribution is related to their physical and chemical properties and is related to the mechanism for forming anodic alumina films. Hydrogen in anodic alumina films separated from Al substrates was determined by a neutron-induced prompt gamma-ray analysis (PGA) system installed at an atomic reactor. Trace hydrogen was determined by liquid scintillation counting method for tritium in barrier films formed in an electrolyte containing tritium water. The hydrogen depth profile was measured after steps were etched into barrier films. Anodic alumina films consist of inner and outer parts, with electrolyte anions distributed to a depth half way from the outer electrolyte/oxide surface but not detected near the inner oxide/metal surface. Otherwise, 0.0035wt% hydrogen was distibuted throughout in the entire depth. We concluded that OH acts as a carrier, migrating to the oxide/metal surface and reacting with Al3+ near the oxide/metal interface.