Universal Scaling in the Temperature-Dependent Viscous Dynamics of Metallic Glasses

The essential query about glass formation is how to understand the sheer temperature dependence of viscous dynamics of glass-forming liquids near the liquid-to-glass-transition temperature T_g. In this work, we report a universal scaling in the temperature-dependent viscous dynamics of metallic glasses (MGs) in the form of the Williams-Landel-Ferry equation on the basis of compiled data on the temperature-dependent viscosity and structural relaxation times of 89 MGs ever-reported in the past decades. Implications of this universal scaling are illustrated in the framework of the Adam-Gibbs relation, suggesting a universal vitrification mechanism in MGs mediated by configurational entropy wherein configurational entropy vanishes universally for all supercooled metallic liquids after a further decrease in temperature of ∼170.7 K (whereas with a relatively large error of ±150 K) below T_g. This result corroborates the thermodynamic origin of glass formation and suggests that MGs are an ideal research subject for understanding in depth the nature of glass transition for their relatively simple molecular structures.