A composition-dependent thermal behavior of Si20Te80−xSnx glasses: Observation of Boolchand intermediate phase

Abstract

Thermal properties have been investigated using alternating differential scanning calorimetry (ADSC) for determining the phase transitions of Si20Te80−xSnx glass samples (1 ≤ x ≤ 6). Experiments are performed to assess the variations of thermal characteristics such as glass transition temperature (Tg) and crystallization temperature (Tc) etc. as a function of Sn variation. The glass-forming ability (GFA) and thermal stability (ΔT) are analyzed for understanding the suitability of as-prepared material in terms of network connectivity and rigidity. The studies have revealed minimum non-reversing enthalpy (ΔHNR) value between compositions (2 ≤ x ≤ 5) of Si20Te80−xSnx glasses, which serve as a basis of the existence of Boolchand's intermediate phase (BIP). It is observed that an increase in Sn dopant resulted in an increase in the density and decrease in the molecular volume of Si20Te80−xSnx samples. These studies reveal the correlation with the memory switching behavior displayed by Si20Te80−xSnx glasses.