Abstract
Agx(Ge0.25Se0.75)100 x glasses with x varying from 0 to 25 have been shown to exhibit a conductivity threshold around x ~8-10. In this work, the structural changes induced by introduction of Ag in Ge25Se75 glass have been investigated using Raman and infra-red spectroscopies. In ambient conditions, changes are observed in position, width and intensity for vibrations assigned to Ge-Se bonds, showing that the tetrahedral network is relaxed and gains flexibility as Ag is introduced. High pressure experiments on two glasses containing 5 and 25 at.% Ag confirm that Ag-rich (25%) glasses clearly exhibit higher compressibility than Ag-poor (5%) glasses.