Solid-liquid surface tensions of critical nuclei and nucleation barriers from a phase-field-crystal study of a model binary alloy using finite system sizes.
Solid-liquid surface tensions of critical nuclei and nucleation barriers from a phase-field-crystal study of a model binary alloy using finite system sizes.
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DOI：
10.1103/physreve.90.022403
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发表时间：
2014-08
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影响因子：
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通讯作者：
M. Choudhary;J. Kundin;H. Emmerich;M. Oettel
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文献类型：
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作者：
M. Choudhary;J. Kundin;H. Emmerich;M. Oettel
相场-晶体(PFC)模型是解决原子长度和扩散时间尺度上晶体生长现象的一种有效的计算工具。在Elder等人的基础上，我们使用了一个二维相场晶体模型来描述一个二元系统。[物理。B 75,064107(2007年)]研究临界核及其液-固相界面，特别是液-固界面张力和成核势垒对核尺寸的依赖关系。临界核在不同大小的有限系统中是稳定的，但提取的界面张力作为核半径r的函数与系统大小无关。对于液-固体系，我们提出了一个唯象表达式来描述提取的界面张力与原子核半径r的关系。数值预测结果表明，这种依赖关系不能完全用非经典的Tolman公式来描述。
Phase-field-crystal (PFC) modeling has emerged as a computationally efficient tool to address crystal growth phenomena on atomistic length and diffusive time scales. We use a two-dimensional phase-field-crystal model for a binary system based on Elder et al. [Phys. Rev. B 75, 064107 (2007)] to study critical nuclei and their liquid-solid phase boundaries, in particular the nucleus size dependence of the liquid-solid interface tension as well as of the nucleation barrier. Critical nuclei are stabilized in finite systems of various sizes, however, the extracted interface tension as function of the nucleus radius r is independent of system size. We suggest a phenomenological expression to describe the dependence of the extracted interface tension on the nucleus radius r for the liquid-solid system. Moreover, the numerical PFC results show that this dependency can not be fully described by the nonclassical Tolman formula.