Raman and infrared studies of the structure of gallium sulphide based glasses

With different compounds such as Na2S, GeS2, Bi2Se3, Ag2S, etc., Ga2S3 forms stable glasses having a large region of composition. In this paper we study the role of gallium sulphide in the glass structure. Two classes of materials are observed: glasses in which Ga2S3 acts as the glass former and glasses for which it is the modifier. Phase diagrams of binary and ternary glass systems are reported and the structure of these glasses are studied by Raman and infrared spectroscopies. According to the relative proportion of gallium atoms in the vitreous matrix, the observed frequencies are assigned to internal vibrations of tetrahedral GaS4 groups and sulphur bridge stretching of corner-shared or edge-shared tetrahedra.