In view of environmental concerns, ozonated water treatment was studied as a replacement for conventional chromic acid etching of plating on ASA Resin. Ozonated water treatment achieves favorable adhesion without roughening the plastic's surface. Chemical analysis and cross-sectional observations show the formation of polar groups on the surface of the treated resin. Catalytic palladium particles are dispersed and adsorbed into the treated resin surface layer after the catalyzing step. Nickel ions penetrate and scatter into the treated resin layer during electroless nickel plating. These observations prove that favorable adhesion can be attributed to the formation of a nanoscale reformed layer, which is completely different from the conventional anchor effect produced using chromic acid etching.
Gallium selenide (GaSe) films, a layered semiconductor, were prepared on silica glass substrates by electron beam deposition at various substrate temperatures (Ts=R. T. ~500ºC). The structure, growth and optical properties of the GaSe films were studied. The unit layer of GaSe films was grown toward the two directions on silica. It is revealed that the GaSe films deposited at R. T. ~300ºC have amorphous structures, while those at 500ºC have a polycrystalline structure with their c-axis perpendicular to the substrate plane. Also it was found that the crystalline structure of the film grown at 400ºC is remarkably changed to become a c-axis parallel to the substrate plane and porous thin film. Furthermore, it was shown that the c-axis orientation of GaSe films could be controlled by the substrate temperature. The absorption edges of the GaSe films deposited at 500ºC showed a direct allowed transition with an optical gap of Eg=2.0eV, which was in good agreement with those measured in single crystal GaSe.
AuAg alloy nanowires in the geometrically anisotropic pores of the aluminum anodic oxidation films with a mean diameter of 10nm and depth of 10μm were successfully prepared by the electrodeposition of gold and silver under the bath voltage of 6V AC in a cyanide-free bath (Ag2SO4-HAuBr4-(NH4)2S2O3). The aspect ratio of the alloy nanowires was controlled by changing the electrodeposition time. The maximum position of absorption band due to the transverse surface plasmon resonances of AuAg alloy nanowires shifts to a longer wavelength with an increase of the composition of Au. The color and shading of the anodized aluminum deposited with alloy nanowires were simply tuned in a wide range.