Structural evolution during crystallization of rapidly super-cooled copper melt

Abstract A molecular dynamics simulation is conducted to investigate the structural evolution during the crystallization of a rapidly supper-cooled copper melt. With a new method that can quantify all kinds of clusters, the structural evolution of the identified predominant cluster types which involve more than 81% of the atoms of the system is extensively discussed. It is found that Ostwald's rule of stages is applicable. The liquid-crystal transition experiences several overlapped stages, which are determined by the critical change in number of different structures. In particular, the saturation stage of icosahedrons-like structures is believed to play an important role for stabilizing the super-cooled liquid and breeding the precursor of crystal, the metastable body-centered cubic stage. These findings will extend the understanding on the mechanism of phase transition of liquid copper as well as other metals.