Existence and forming mechanism of metastable phase in crystallization

Understanding and controlling the selection of crystalline structure are of great significance in crystal growth, in which the preparation of metastable crystal structures is one of the most important issues to be understood. Although plenty of experimental and simulation investigations have been carried out to reveal the formation of metastable structures, the mechanism of metastable phase existence and forming still remains unclear. In the present work, by using the phase field crystal (PFC) model, we further explored the existence and formation mechanism of metastable structure by modeling the crystallization process with prestructured seeds in 2D. We found that the metastable structure can be survived in a certain region of the phase diagram. Our results show that the selection of final structures is determined not only by the thermodynamic driving force but also by competitions between the metastable and stable structures.