Phase relations in the system sulfur—Silver and the transitions in silver sulfide

TL;DR: The melting relations for the entire system sulfursilver, together with a study of the transition behavior of silver sulfide, were presented in this article, where a discussion was given of a possible mechanism for the incorporation of a limited excess of sulfur or silver into the lattice, as bised on the semiconducting properties of the substance and lattice disorder.

Abstract: This paper presents the melting relations for the entire system sulfursilver, together with a study of the transition behavior of silver sulfide. Silver sulfide melts at 838±2°C and undergoes two transitions in the solid state, each of which occurs at variable temperatures over a limited range of composition. The mean temperatures for the lower transition (Ag2S III=Ag2S II) are 177.8°C in sulfur-rich and 176.3°C for silver-rich preparations; for the upper transition (Ag2S II=Ag2S I) they are, respectively, 622°C and 586°C. A discussion is given of a possible mechanism for the incorporation of a limited excess of sulfur or silver into the lattice, as bised on the semi-conducting properties of the substance and lattice disorder The melts of silver sulfide form two liquid layers with sulfur-rich melts at 740°C, and with silver-rich melts at 906°C. The eutectic with sulfur is at 119.3°C, and with silver, at 804°C.