Molecular simulation of the crystallization of aluminum from the supercooled liquid
Molecular simulation of the crystallization of aluminum from the supercooled liquid
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DOI：
10.1063/1.2784120
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发表时间：
2007-10-14
影响因子：
4.4
通讯作者：
Delhommelle, Jerome
中科院分区：
文献类型：
--
作者：
Desgranges, Caroline;Delhommelle, Jerome
我们报告了铝从过冷液体中结晶的混合蒙特卡罗分子模拟结果。我们在 P=1 atm 和低于熔化温度 20% 和 15% 的温度下模拟整个结晶过程。我们证明，对于本工作中考虑的两种过冷度，结晶是根据相同的机制发生的。我们表明，成核和生长都进入六方密堆积结构和面心立方（fcc）相的随机混合，其中稳定的 fcc 形式占主导地位。研究发现过冷液体中二十面体 (Ih) 类原子的浓度在整个成核和生长过程中保持恒定，这表明类 Ih 原子在结晶过程中并未发挥积极作用。我们还发现铝的结晶机制与简单流体观察到的不同。虽然简单流体的成核首先进入亚稳态体心立方 (bcc) 相，但铝微晶中类 bcc 原子的比例始终保持很低。 (C) 2007 年美国物理研究所。
We report hybrid Monte Carlo molecular simulation results on the crystallization of aluminum from the supercooled liquid. We simulate the entire crystallization process at P=1 atm and at temperatures 20% and 15% below the melting temperature. We demonstrate that crystallization takes place according to the same mechanism for the two degrees of supercooling considered in this work. We show that both nucleation and growth proceed into a random mixing of the hexagonal close packed structure and of the face centered cubic (fcc) phase, with a predominance of the stable fcc form. The concentration of icosahedral (Ih)-like atoms in the supercooled liquid is found to remain constant throughout nucleation and growth, showing that Ih-like atoms do not play an active role in the crystallization process. We also find that the crystallization mechanism of aluminum differs from that observed for simple fluids. While nucleation of simple fluids first proceeds into the metastable body centered cubic (bcc) phase, the fraction of bcc-like atoms in aluminum crystallites always remains very low. (C) 2007 American Institute of Physics.