Fig. 3: Glass transition.
From: The potential of chemical bonding to design crystallization and vitrification kinetics
a Dependence of the reduced onset temperature Tro for glass formation upon ES (for the crystalline phase). Tro was measured at a heating rate of 60,000 K/min. Replacing Te in GeTe by Se leads to a significant increase in glass-forming ability as characterized by Tro. b Correlation between the minimum time of crystallization τ and Tro. Ultrafast crystallization (low values of τ) is accompanied by low glass stability (small values of Tro). Interestingly, compounds on the pseudo-binary line between GeTe and Sb2Te3, such as Ge2Sb2Te5 are characterized by ultrafast crystallization, but slightly improved stability of the glassy state. Tro data are extrapolated from powder samples (see Methods section).
