Structural and electrical properties of some TeAsGeS glasses

Electrical and DTA measurements have been performed on TeAsGeS glasses. In this group, As 2 Te n Ge (4 ⩽ n ⩽ 7) glasses are of particular interest since, in the AsTeGe vitrigfication diagram, they all are located on a straight line crossing completely one of the two vitrification regions. The comparison of the results of DTA on As 2 Te 3 , Te 4 Ge and As 2 Te n Ge (4 ⩽ n ⩽ 7) shows that the structure of the As 2 Te n Ge glasses is built around the Ge atoms. The electrical properties of a particular family whose composition is near As 2 Te 5 Ge + S as vitrificant agent are given. Photoelectron spectroscopy has also been used for an investigation of the structure of this last family and permits to conclude that in the crystallized state, phase separations occur.