Molecular dynamics simulation of crystal growth in Al50Ni50: The generation of defects

The ordering processes in the interface of a solidifying binary alloy (Al50Ni50) are studied by molecular dynamics computer simulation. At various temperatures below the melting point, inhomogeneous systems with planar crystal-melt interfaces in (100) orientation are prepared. The growth of a new crystalline Al or Ni layer proceeds through different time-delayed ordering processes. Before the onset of crystallization, there is a segregation process of Al and Ni atoms in the region where a new layer forms. We show that the interplay between segregation and crystallization supports the formation of a high nonequilibrium concentration of point defects. DOI: 10.1103/PhysRevB.87.014105