Relation between Thermodynamics and Kinetics of Glass-Forming Liquids

Abstract

Vitrification of a supercooled liquid is often characterized by the hypothetical kinetic instability point, the Vogel-Fulcher temperature $T_0$, and the thermodynamic one, the Kauzmann temperature $T_K$. The widely believed relation $T_0\cong T_K$ is regarded as the supporting evidence of a direct connection between the thermodynamics and kinetics of glass-forming liquids. Here we demonstrate that $T_K/T_0$ systematically increases from unity with a decrease in the fragility, contrary to the common belief. This systematic deviation may be explained by a synergistic effect between the weaker cooperativity and the stronger tendency of short-range ordering in stronger glass formers.