Electrical resistivity behaviour of Ag-Ge-Te glasses under pressure at different temperatures: the influence of bonding and topological thresholds

Abstract

The electrical resistivity of melt quenched Ge-Te glasses containing Ag has been studied as a function of pressure at different temperatures in a Bridgman anvil set-up. The samples are found to exhibit a continuous decrease in electrical resistivity with pressure and metallization around 5 GPa. The pressure dependence of conductivity activation energy ( Δ E) also confirms the continuous metallization of Ag_xGe₁₅Te_85-x glasses. The variation of Δ E with composition at different pressures has been found to exhibit anomalies at x = 5 and x = 18.5. A plausible explanation based on the bonding considerations, topological thresholds and density variations with composition has been provided to understand the conductivity activation energy of Ag-Ge-Te and other chalcogenide glasses.