The ability of a body-centered-cubic metal to deform plastically is limited by the thermally activated glide motion of screw dislocations, which are line defects with a mobility exhibiting complex dependence on temperature, stress, and dislocation segment length. We derive an analytical expression for the velocity of dislocation glide, based on a statistical mechanics argument, and identify an apparent phase transition marked by a crossover temperature above which the activation energy for glide effectively halves, changing from the formation energy of a double kink to that of a single kink. The analysis is in quantitative agreement with direct kinetic Monte Carlo simulations.

中文翻译：

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滑行螺钉脱位的扭结统计力学

体心立方金属塑性变形的能力受到螺钉位错的热活化滑动运动的限制，螺钉位错是一种线缺陷，其迁移率表现出对温度，应力和位错链段长度的复杂依赖性。我们根据统计力学论据推导了位错滑移速度的解析表达式，并确定了一个以交叉温度为标志的表观相变，在该温度以上，滑移的激活能有效地减半，从双扭结的形成能变为一个单一的扭结。该分析与直接动力学蒙特卡洛模拟在数量上一致。