To Predict The Theoretical Model Of The Material Crystallinity

Materials of single crystal structures that exhibit a lot of superior properties have been widely used in many fields. Because of these excellent properties, continuous efforts have been made to prepare single crystals with larger volume and better structure. In fact, the ability to form different structures of single crystals may considerably differ from one another. For example, single crystal quartz with size of several 10 cm can be easily produced in common experiments, while it is difficult to get diamond grains of only several millimeters even under extreme conditions. So it is urgent in materials design to develop a theory to accurately predict the crystallizing ability.Recently, we proposed a condensing potential (CP) model to evaluate the ability of materials to form single crystals, and demonstrated that the ability of some single-component crystals (Ni, Al, Cu, Ar and Mg) increases monotonically with increasing CP. Since the prediction can be easily performed via common ab initio methods, the theory is promising to predict the ability of multi-component materials to form single crystals, which are more common in practice. In the present work, we extended the CP model to two-component systems, and specifically investigated the Al doping (0-6 wt.%) influence on the crystallizing ability of Ni-based crystal and the Au doping (6 wt.%,17 wt.%,30 wt.%) influence on the crystallizing ability of Cu-based crystal. Extensive molecular dynamic (MD) simulations were performed to examine the crystal growth and showed that the A1 doping of only 6 wt.% will considerably decrease the crystallizing ability of the pure crystal but even 30% Au does not. As expected, the ability of the two-component materials to form single crystals also increased monotonically with increasing CP. Then we employed the extended CP model to investigate the crystallizing abilities of Ni3Al crystal and C3N4 crystal. Our predictions were well in agreement with the experimental data, exhibiting a prospect of CP model in predicting the ability of multi-component materials to form single crystals.