The presence of a thermally reversing window in Al–Te–Si glasses revealed by alternating differential scanning calorimetry and electrical switching studies

Abstract

Alternating differential scanning calorimetric (ADSC) studies and electrical switching experiments have been undertaken on Al15Te85−xSix (2⩽x⩽12) system of glasses. These glasses are found to exhibit two crystallization reactions (Tc1 and Tc2), for compositions with x<8. Above x=8, a single-stage crystallization is seen. Further, a trough is seen in the composition dependence of non-reversing enthalpy (ΔHNR), based on which it is proposed that there is a thermally reversing window in Al15Te85−xSix glasses, in the composition range 4⩽x⩽8. Electrical switching studies indicate that Al15Te85−xSix glasses exhibit a threshold type electrical switching at ON state currents less than 2mA. Further, the switching voltages are found to increase with the increase in silicon content. It is interesting to note that the start (x=4) and the end (x=8) of the thermally reversing window are exemplified by a kink and a saturation in the composition dependence of switching voltages, respectively.