Density Scaling of Glassy Dynamics and Dynamic Heterogeneities in Glass-forming Liquids.

The discovery of density scaling in strongly correlating systems is an important progress for understanding the dynamic behaviors of supercooled liquids. Here we found for a ternary metallic glass-forming liquid, it is not strongly correlating thermodynamically, but its average dynamics, dynamic heterogeneities and static structure are still well described by density scaling with the same scaling exponent $\gamma $. As an intrinsic material constant stemming from the fundamental interatomic interactions, $\gamma $ is theoretically predicted from the thermodynamic fluctuations of potential energy and the virial. Although $\gamma $ is conventionally understood merely from the repulsive part of the inter-particle potentials, the strong correlation between $\gamma $ and the Grüneisen parameter up to the accuracy of the Dulong-Petit approximation demonstrates the important roles of anharmonicity and attractive force of the interatomic potential in governing glass transition of metallic glass-formers. The supercooled dynamics and density scaling behaviors will also be discussed in model glass-forming liquids with tunable attractive potentials to further quantify the nonperturbative roles of attractive interactions.