Free energy of grain boundary phases: Atomistic calculations for Σ5(310)[001] grain boundary in Cu
Free energy of grain boundary phases: Atomistic calculations for Σ5(310)[001] grain boundary in Cu
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DOI：
10.1103/physrevmaterials.2.093603
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发表时间：
2018-09-10
影响因子：
3.4
通讯作者：
Frolov, Timofey
中科院分区：
文献类型：
--
作者：
Freitas, Rodrigo;Rudd, Robert E.;Frolov, Timofey
原子模拟表明，存在一个定义明确的热力学相变之间的晶界（GB）相具有不同的原子结构。采用非平衡Frenkel-Ladd热力学积分方法，通过分子动力学模拟计算了元素Cu中Sigma 5（310）[001]对称倾斜界面的嵌入原子模型的不同界面结构的自由能.结果表明，自由能曲线预测的温度诱导的一阶界面相变在GB结构与计算研究相同的模型系统。此外，在高温GB相的稳定振动熵的作用是明确的。计算结果是能够确定的GB相稳定性在同源温度小于0.5，温度范围特别重要的限制，迄今为止，在模拟GB相变在低温下的方法。GB自由能的计算补充了目前可用的0 KGB结构搜索方法，使GB相图的表征成为可能。
Atomistic simulations are employed to demonstrate the existence of a well-defined thermodynamic phase transformation between grain boundary (GB) phases with different atomic structures. The free energy of different interface structures for an embedded-atom-method model of the Sigma 5(310)[001] symmetric tilt boundary in elemental Cu is computed using the nonequilibrium Frenkel-Ladd thermodynamic integration method through molecular dynamics simulations. It is shown that the free-energy curves predict a temperature-induced first-order interfacial phase transition in the GB structure in agreement with computational studies of the same model system. Moreover, the role of vibrational entropy in the stabilization of the high-temperature GB phase is clarified. The calculated results are able to determine the GB phase stability at homologous temperatures less than 0.5, a temperature range particularly important given the limitation of the methods available hitherto in modeling GB phase transitions at low temperatures. The calculation of GB free energies complements currently available 0 K GB structure search methods, making feasible the characterization of GB phase diagrams.