Structural evolution during crystallization of rapidly super-cooled copper melt

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. •A detailed structural evolution during crystallization is quantified for copper.•The atoms involved in analysis are more than 81% for all samples concerned.•A series of distinct intermediate stages are uncovered by a new method of LSCA.•Saturated ICOs stabilize the super-cooled melt and breed the metastable bcc state.