An investigation, using the XPS technique, showed that surface diffusion of S occurred on Ag paste. It was found that Ag2S formed at room temperature from a 2H-SnS2 monocrystal which had been synthesized by chemical vapor transport at low temperatures.

T.Shibata, Y.Muranushi, T.Miura, T.Kishi: Journal of the Physics and Chemistry of Solids, 1990, 51[4], 377-9