铜晶体中类层错四面体的结构及其演化

运用分子动力学方法，研究了金属铜单晶中不同形状的Frank位错环演化形成的各种类层错四面体稳定构型.对其形成过程的细致分析表明，这些稳定构型都可以用统一的位错分解和位错反应过程来解释.模拟结果表明，在零温下各种Frank位错环存在各自的临界尺寸，小于临界尺寸的Frank位错环不能长成类层错四面体结构.对梯形、六边形等Frank位错环演化过程的模拟表明，在形成稳定类层错四面体的过程中，存在位错生长和回缩的振荡现象.振荡现象是由于位错间的排斥和吸引相互作用不同步或弹性波传播的延迟效应引起的. 关键词： 层错四面体 位错 分子动力学

Evolution of stacking-fault-tetrahedron-like structures in copper crystal

Transformation of various intrinsic Frank loops into stacking-fault-tetrahedron（SFT）-like structures in single crystal copper is investigated using the molecular dynamics（MD） method. We got stable SFT structures and explained their formation via a unified theory.Simulation results show that there is a critical size for the Frank loops at zero temperature. When being smaller than this critical size, Frank loops can not transform into SFT. Hexagonal and trapezoidal Frank loops exhibit oscillations in the relaxation processe, which is due to the elastic interactions between dislocations as well as the delay effects in the propagation of elastic waves.