Thermal activation analysis of enthalpic and entropic contributions to activation free energy of basal and prismatic slips in Mg
Thermal activation analysis of enthalpic and entropic contributions to activation free energy of basal and prismatic slips in Mg
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Mg 基滑移和棱柱滑移活化自由能的焓和熵贡献的热活化分析
DOI：
10.1103/physrevb.89.224103
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发表时间：
2014
影响因子：
3.7
通讯作者：
R. Matsumoto
中科院分区：
文献类型：
--
作者：
M. Uranagase;R. Matsumoto
采用原子模拟方法研究了镁单晶基滑移和棱柱滑移位错环的形核过程。为了克服在传统的分子动力学模拟中发生的时间尺度的限制，应用元自洽方法。位错环形核的激活自由能也通过metadaptics方法进行评估。特别是，从温度的依赖性，我们表明，线性关系之间的贡献，熵的活化自由能是满意的。我们发现，基底滑移和棱柱滑移的激活自由能对温度的依赖性之间的差异与表面的结构有关。
The nucleation of a dislocation loop for basal and prismatic slips of a magnesium single crystal was studied via atomistic simulations. The metadynamics method was applied in order to overcome the time-scale restrictions that occur in conventional molecular dynamics simulations. The activation free energy of a dislocation loop nucleation is also evaluated via the metadynamics method. In particular, from the temperature dependence, we showed that a linear relationship between the enthalpic and entropic contributions to the activation free energy is satisfied. We found that the difference between the dependence of the activation free energy on the temperature for basal and prismatic slips is related to the structure of thesurface.