In this work, a strong correlation between the density of defected atom pairs at the crystal-liquid interface and the activation energy for crystal growth from deeply undercooled melts is established. Using molecular dynamics simulations we study the intermediate interstitial pairs at the crystal-melt interfaces of both BCC and FCC pure metals. It is found that the pairs have preferred orientations, and two important types of interstitial pairs at the interfaces are identified according to their orientations. We demonstrate that the relative amount of these two kinds of interstitial pairs varies greatly for different systems and dominates the activation energy for crystal growth. The dependence of local structure and energy on the orientation of the interfacial interstitial pairs are revealed and the connections of these features with crystal growth kinetics are disclosed.

在这项工作中，建立了晶体 - 液体界面处缺陷原子对的密度与深度过冷熔体晶体生长的活化能之间的强相关性。我们使用分子动力学模拟研究了 BCC 和 FCC 纯金属的晶体-熔体界面处的中间间隙对。发现这些对具有优选的方向，并且根据它们的方向识别界面处的两种重要类型的间隙对。我们证明了这两种间隙对的相对数量对于不同的系统差异很大，并且主导了晶体生长的活化能。