Glass transitions of Te-based phase-change materials (PCMs) were studied by modulated differential scanning calorimetry. It was found that both Ge 2 Sb 2 Te 5 and GeTe are marginal glass formers with ΔT (= T x % T g ) less than 2.1°C when the heating rate is below 3°C min %1. The fragilities of Ge 2 Sb 2 Te 5 and GeTe can be estimated as 46.0 and 39.7, respectively, around the glass transition temperature, implying that a fragile-to-strong transition would be presented in such Te-based PCMs. The above results provide direct experimental evidence to support the investigation of crystallization kinetics in supercooled liquid PCMs.

No abstract

The crystal growth rates of supercooled liquids In–Sb–Te can be well characterized by ultrafast DSC, and it benefits to the optimization for phase-change materials.