Reference

Field ion microscopy and mass spectroscopy of sulfur covered silver surfaces

Field ion microscopy and mass spectroscopy of sulfur covered silver surfaces. Hayek, K.; Frank, O.; Schmidt, W. A.; Block, J. H. (Fritz-Haber-Inst., Max-Planck-Ges., Berlin, Ger.). Ber. Bunsenges. Phys. Chem., 81(3), 262-8 (English) 1977. CODEN: BBPCAX. DOCUMENT TYPE: Journal CA Section: 66 (Surface Chemistry and Colloids) Section cross-reference(s): 76 Field desorption from clean and S-covered Ag field emitters was studied by field ion microscopy and mass spectrometry. The evapn. rate of Ag+ was measured as a function of S coverage and after formation of different surface structures at different temps. After satn. of the surface with S, field desorption of Ag+ occurred and no S species were detected. The evapn. field of Ag+ was lowered by >50% after max. S coverage, but the amt. of Ag+ desorbed was not limited by the amt. of surface sulfide. Anionic species on the surface facilitate the transition of metallic Ag into the vacuum ionic state.Except for chemicals metioned above, 7440-22-4 and 21548-73-2 are also used. The high mobility of Ag+ in Ag2S as well as the enhancement of surface mobility of Ag after contamination are considered. .

Tarnishing resistance of silver-palladium thin films

All Rights Reserved. Tarnishing resistance of silver-palladium thin films. Doriot-Werle, M.; Banakh, O.; Gay, P.-A.; Matthey, J.; Steinmann, P.-A. (HE-ARC, University of Applied Sciences, Le Locle CH-2400, Switz.). Surface and Coatings Technology, 200(24), 6696-6701 (English) 2006 Elsevier B.V. CODEN: SCTEEJ. ISSN: 0257-8972. DOCUMENT TYPE: Journal CA Section: 56 (Nonferrous Metals and Alloys) Ag-Pd decorative coatings are supposed to provide better tarnishing resistance as compared to pure Ag, while keeping good optical (brightness) and mech. properties (ductility). Palladium has a similar optical appearance as silver, and forms a thin protective oxide surface layer. Thus, a small incorporation of Pd in Ag could improve its tarnishing resistance. Thin Ag-Pd films were deposited by magnetron co-sputtering from Pd and Ag targets.Several substances with their cas registry numbers 66199-16-4 and 21548-73-2 may be metioned in this study. The Ar gas pressure, target power, and substrate temp. were varied to modify the chem. compn. of the films and optimize their properties. The optical properties of the films were evaluated by spectroscopic ellipsometry and colorimetry. Increasing Ar gas pressure and substrate temp. results in a drastic decrease of the specular reflectivity of the films. At const. deposition conditions the reflectivity of the Ag-Pd films decreases with increasing Pd content. The film hardness, evaluated by nanoindentation, increases with Pd content. The tarnishing resistance of the films was evaluated by sulfidation tests. The color change of the films due to the sulfidation was measured by colorimetry. The nature of chem. bonds of the tarnished products was evidenced by XPS. The results suggest an improvement of tarnishing resistance of the Ag-Pd films with increasing Pd content. .