Onset of Cooperative Dynamics in an Equilibrium Glass-Forming Metallic Liquid

Onset of cooperative dynamics has been observed in many molecular liquids, colloids, and granular materials in the metastable regime on approaching their respective glass or jamming transition points, and is considered to play a significant role in the emergence of the slow dynamics. However, the nature of such dynamical cooperativity remains elusive in multicomponent metallic liquids characterized by complex many-body interactions and high mixing entropy. Herein, we report evidence of onset of cooperative dynamics in an equilibrium glass-forming metallic liquid (LM601: Zr51Cu36Ni4Al9). This is revealed by deviation of the mean effective diffusion coefficient from its high-temperature Arrhenius behavior below T-A approximate to 300 K, i.e., a crossover from uncorrelated dynamics above T-A to landscape-influenced correlated dynamics below T-A. Furthermore, the onset/crossover temperature T-A in such a multicomponent bulk metallic glass-forming liquid is observed at approximately twice of its calorimetric glass transition temperature (T-g approximate to 697 K) and in its stable liquid phase, unlike many molecular liquids.