Properties and Structure of Glasses in the System As₂S₃-Sb₂S₃-S

Abstract

The authors have previously reported a structural studies of the glasses in the system As2S3-Sb2S3 and the analogous studies of the glasses in the pseudo-ternary system As2S3-Sb2S3-S are described in this paper.Such properties as density, thermal expansion, infra-red absorption, vickers hardness, and extraction of ring type sulfur (S8) with CS2, have been measured for the As2S3-Sb2S3-S glasses and, in addition, X-ray diffraction studies of aAs2S5⋅bSb2S3 glasses (b/a=0/8, 1/7, 2/6, 3/5, 4/4, and 5/3) have been performed.The radial distribution curve of the As2S5 glass was subtracted from the distribution curve obtained for each glass, taking into account the molecular content of As2S5. The first peak in the resultant curve is found to correspond in area to the sum of the peaks due to the Sb-S pair (2.54A) and the S-S pair (2.04A). It implies that the series of the As2S5-Sb2S3 glasses have the microheterogeneous structure composed of As2S5 and Sb2S3 regions that are joined together by the As-S-S-Sb linkages.In addition to X-ray diffraction study, the results obtained from the study of other properties permit the following conclusion. When sulfur is added to the As2S3-Sb2S3 glasses (the microheterogeneous structure consisting of both As2S3 and Sb2S3 regions) it enters only into the As2S3 region. Subsequently the As2S3region alters to the As2Sx(x>3) region whose structure is similar to that of the As-S glasses. Sulfur taken part in the As2Sx(x>3) region exists only as the chain type sulfur in the composition range of small sulfur content but, at higher sulfur content, not only the chain type sulfur but also the ring type sulfur exists in the glass structure.Consequently, in the system As2S3-Sb2S3-S, the glasses have the microheterogeneous structure composed of the As2Sx(x>3) and Sb2S3 regions that joined together by the As-S-S-Sb linkages.