Abstract
The kinetics of the annealing of vacancies in finite monolayer patches of several thousand particles have been studied by molecular dynamics for three central force interactions; the nearest-neighbour piecewise linear force potential, the Lennard-Jones potential and the similar ( r −8 − r −4) potential. The simplest behaviour observed is the diffusion of the vacancies to the nearest basin of attraction; the edges or a larger concentration of vacancies, forming in the latter case voids. The voids in turn migrate to the next attractor, forming larger voids, until all vacancies are annealed. A rapid dislocation mediated healing (DMH), which removes most of the vacancies with the dislocations annealing out of the system, can be observed with a long-range interparticle interaction. Mobile vacancies and pressure also favour the phenomenon. DMH can occur well below the self-diffusion temperature of vacancies. A ‘void-dislocation dipole’ reversible conversion is observed with some small vacancy clusters in systems exhibiting both annealing processes. The relevance of this study to bulk annealing kinetics is discussed.
Published Version
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