Thermodynamic, Raman and electrical switching studies on Si15Te85-xAgx (4 ≤ x ≤ 20) glasses

We have investigated thermal properties of bulk Si15Te85-xAgx (4 ≤ x ≤ 20) glasses in detail, through alternating differential scanning calorimetry experiments. The composition dependence of thermal parameters reveal the signatures of rigidity percolation and chemical threshold at compositions x = 12 and x = 19, respectively. The stability and glass forming ability of these glasses have also been determined using the data obtained from different thermodynamic quantities and it is found that the Si15Te85-xAgx glasses in the region 12 ≤ x ≤ 17 are more stable when compared to other glasses of the same series. Further, the blueshift observed in Raman spectroscopy investigations, in the composition range 12 ≤ x ≤ 13, support the occurrence of stiffness threshold in this composition range. All Si15Te85-xAgx (4 ≤ x ≤ 20) glasses are found to exhibit memory type switching (for sample thickness 0.25 mm) in the input current range 3-9 mA. The effect of rigidity percolation and chemical thresholds on switching voltages are observed at x = 12 and 19, respectively.