Heterogeneous cavitation and crystallisation with an impurity by molecular dynamics

A homogeneous metastable liquid system and a heterogeneous system with an immersed impurity were used to investigate the cavitation and crystallisation characteristics by molecular dynamics. An isochoric quench was conducted to the systems, which initially produced a cavity, where the entire system subsequently crystallised. The systems with the impurities showed an overall increase in the crystal nucleation rate and a modest but clear shape effect was observed. Similar to previous droplet condensation studies, a clear curvature effect was observed to influence the rate of the phenomenon. At the onset of quenching, crystallisation occurred on the faces of the seed, so a flat surface promoted local crystallisation, which propagated the formation of the cavity, and thereafter increased the density of the metastable liquid, so to advance overall crystallisation within the system.