Thermal stability and structure of Ge-Sb-S glasses

Sb-S binary glass samples with a batch composition of Sb33.3S66.7 could be obtained by a melt-quenching method using a vacuum-sealed silica ampoule. The glass transition temperature of Sb33.3S66.7 glass was 163degreesC. Two series of Ge-Sb-S ternary glasses, namely GeS2-SbS1.5 and GeS2-SbS2 were also prepared. The Ge-Sb-S glasses at 20-40 mol% SbS2 possess relatively-high thermal stability with the difference between glass transition and onset crystallization temperatures over 200degreesC. The compositional dependence of molar volume calculated from measured density was evaluated for Ge-Sb-S glass samples. Raman spectroscopy revealed that Ge-Sb-S glasses consist mainly of GeS4 tetrahedra and SbS3 pyramids and the SbS2 glass is composed of SbS3 pyramids. Additionally Ge-Sb-S glasses at 20-50 mol% SbS2 in a series of GeS2-SbS2 contain S-S bonds.