Effect of topological thresholds on thermal behaviour of germanium telluride glasses containing metallic additive

Differential Scanning Calorimetric (DSC) studies on AgxGe15Te85-x glasses h ave been undertaken over a wide range of compositions, to understand the ef fect of topological thresholds on thermal properties. It is found that the compositional dependence of glass transition temperature (T-g), crystalliza tion temperature (T-c), activation energy for crystallization (Delta E) and thermal stability (Delta T) show anomalies at the rigidity percolation thr eshold. Unusual variations also observed in different thermal properties at the composition x = 20, clearly establishes the occurrence of chemical thr eshold in these glasses.