The electrical switching and thermal behavior of bulk Ge15Te85 − xSnx and Ge17Te83 − xSnx glasses

Bulk Ge15Te85 − xSnx and Ge17Te83 − xSnx glasses, are found to exhibit memory type electrical switching. The switching voltages (Vt) and thermal stability of Ge15Te85 − xSnx and Ge17Te83 − xSnx glasses are found to decrease with Sn content. The composition dependence of Vt has been understood on the basis of the decrease in the OFF state resistance and thermal stability of these glasses with tin addition. X-ray diffraction studies reveal that no elemental Sn or Sn compounds with Te or Ge are present in thermally crystallized Ge–Te–Sn samples. This indicates that Sn atoms do not interact with the host matrix and form a phase separated network of its own, which remains in the parent glass matrix as an inclusion. Consequently, there is no enhancement of network connectivity and rigidity. The thickness dependence of switching voltages of Ge15Te85 − xSnx and Ge17Te83 − xSnx glasses is found to be linear, in agreement with the memory switching behavior shown by these glasses.