Heredity of clusters in the rapidly cooling processes of Al-doped Zr50Cu50 melts and its correlation with the glass-forming ability*

The heredity of clusters in rapidly cooled (Zr50Cu50)(100 - x )Al- x melts and its correlation with glass-forming ability (GFA) are studied via molecular dynamics simulations. Pair distribution function and the largest standard cluster (LSC) are adopted to characterize the local atomic structures in the (Zr50Cu50)(100 - x )Al- x systems. The [12/555] icosahedra and their medium-range order (IMRO) play an important role in forming (Zr50Cu50)(100 - x )Al- x metallic glasses (MGs). The fraction of [12/555], the number of IMRO, and the maximum size of IMRO in MGs increase significantly with increasing x. A tracking study further reveals that the configuration heredity of icosahedral clusters starts from supercooled liquids. No direct correlation exists between the GFA and the onset temperature of continuous or stated heredity. Instead, a larger hereditary supercooled degree of icosahedra matches with better GFA of Al-doped Zr50Cu50 alloys.