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

Abstract

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.

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