The peierls energy and kink energy in fcc metals
The peierls energy and kink energy in fcc metals
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DOI：
10.1080/14786430412331314654
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发表时间：
2005-03
影响因子：
1.6
通讯作者：
Gunther Schoeck §;M. Krystian
中科院分区：
文献类型：
--
作者：
Gunther Schoeck §;M. Krystian
在面心立方晶体中，位错在{111}滑移面上解离成部分位错对。由于每个部分单独与 Peierls 势相互作用，并通过堆垛层错与其相邻部分耦合，因此当沿着闭堆积晶格方向运行的位错发生位移时，部分部分的间隔距离 d 会出现周期性变化。这可以大大减少有效 Peierls 应力。利用 Peierls 模型，研究了具有 Cu 弹性特性且堆垛层错能 γ0 在 0.04 ≤ γ0 ≤ 0.05 J/m2 范围内的典型面心立方金属中的 0°、30°、60° 和 90° 位错结构，并确定了 Peierls 能量 ΔE P 的大小和由此产生的扭结能 E K。由于所涉及的能量约为 10−3 eV/b 或更小，因此考虑到模型中的简化假设，无法以高置信度断言其大小。然而，不同方向位错位移过程中核心构型变化的差异应该具有物理意义。研究发现，解离 60° 位错通常比螺旋位错具有更高的有效 Peierls 能量，但扭结能量则相反，至少在 Cu 中是这样。
In fcc crystals, dislocations are dissociated on the {111} glide plane into pairs of partial dislocations. Since each partial interacts individually with the Peierls potential and is coupled to its neighbour by a stacking fault, periodic variations in the separation distance d of the partials occur when dislocations running along closed packed lattice directions are displaced. This can drastically reduce the effective Peierls stress. By using the Peierls model the structure of 0°, 30°, 60° and 90° dislocations in a typical fcc metal with the elastic properties of Cu and a stacking-fault energy γ0 in the interval 0.04 ≤ γ0 ≤ 0.05 J/m2 was studied, and the magnitude of the Peierls energy ΔE P and the resulting kink energies E K were determined. Since the energies involved are of the order of 10−3 eV/b or less, their magnitude cannot be asserted with high confidence, considering the simplifying assumptions in the model. The difference in the changes of the core configuration during displacement of dislocations of different orientations should, however, be of physical significance. It is found that a dissociated 60° dislocation generally has a higher effective Peierls energy than a screw dislocation, but the reverse is true for the kink energy, at least in Cu.