Understanding the unusual-caged dynamics from the microstructure and interatomic interactions in binary metallic glass-forming liquids

The caged dynamics appears at time shorter than the fl -relaxation but longer than the boson peak. Due to the limitations of experimental conditions, the mechanism of caged dynamics is not well studied in metallic glasses. We study a model La65Al(35) glass-forming liquid with strong atomic interactions that presents an unusual caged dynamics, and the La65Ni35 GF liquid is also studied to clarify the underlying mechanisms of caged dynamics. There is a sudden drop near 0.1 ps in the partial non-Gaussian parameter of Al atoms, reflecting the development of caging of the Al atoms with time. A similar feature is also found in Ni80P20, Sm80Al20, Pd80Si20, and Y80Mg20 metallic GF liquids. The chemical order, Voronoi polyhedra, and covalent-like bonds are all related to the cage-breaking behavior of the central atoms, in turn regulating the unusual caged dynamics. These findings shed light on the complex relaxation dynamics of GF liquids.

Automated summary

The study reveals the existence of unusual caged dynamics in metallic glass-forming liquids with strong atomic interactions. The mechanism of caged dynamics is found to be related to chemical order, Voronoi polyhedra, and covalent-like bonds.