Peierls potential for crowdions in the bcc transition metals
Peierls potential for crowdions in the bcc transition metals
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DOI：
10.1103/physrevlett.101.115504
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发表时间：
2008-09-12
影响因子：
8.6
通讯作者：
Nguyen-Manh, D.
中科院分区：
文献类型：
--
作者：
Fitzgerald, S. P.;Nguyen-Manh, D.
本文首次推导了基于双sine-Gordon模型的Peierls-Nabarro势的解析表达式。该分析由周期表的5 B和6 B族中的体心立方过渡金属计算的周期晶格势的形状中的组特定趋势指导。我们结合联合收割机密度泛函计算crowdion的配置文件和环境的分析Frenkel-Kontorova模型的扩展版本，并确定所经历的缺陷的质心的有效潜力。这揭示了这些组中的金属之间的重要的潜在差异，这是无法单独使用数值或分析方法的，并解释了先前无法解释的在6 B组金属中观察到的相对于5 B组金属的显著更高的crowdion迁移温度。
We present the first derivation of the analytic expression for the Peierls-Nabarro potential for crowdion migration using the double sine-Gordon model. The analysis is guided by the group-specific trend in the shapes of the periodic lattice potentials calculated for the body-centered-cubic transition metals in groups 5B and 6B of the periodic table. We combine density-functional calculations of the crowdion's profile and environment with an extended version of the analytical Frenkel-Kontorova model, and determine the effective potential experienced by the defect's center of mass. This reveals important underlying differences between the metals in these groups, which are inaccessible to either the numerical or analytical approaches alone, and accounts for the previously unexplained significantly higher crowdion migration temperatures observed in the metals of group 6B relative to those of group 5B.