Ellipsometric analysis for growth of Ag/sub 2/S film and effect of oil on corrosion resistance of Ag contact surface

By applying ellipsometric analysis, the growth laws of Ag/sub 2/S film on Ag contact surface exposed to H/sub 2/S gas environment at the rate of 3 p.p.m., 80-85% RH, at 40 degrees C were determined. Parameters for corrosion kinetics related to the growth law of Ag/sub 2/S film were obtained. The growth rate of the film decreased in four stages, as the sulfuration time became longer. The lowering of the growth rate was found to correspond to microscopic changes in the surface morphology. The contact resistance property was deteriorated by growth of Ag/sub 2/S film thicker than 500-750 AA. The effect of a stearic acid coating on corrosion resistance was confirmed. The optimum thickness of the oil film to sustain low contact resistance was found; this thickness is around several hundred AA.<
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