Melting of Dislocation Vector Systems in Two Dimensions

Abstract

A Monte Carlo study of a system of interacting dislocation vectors reveals the possibility of two types of phase transitions. For a system with a large dislocation core energy, unbinding of dislocation pairs causes a continuous phase transition. With a small core energy a first-order transition is produced by formation of grain boundaries. This possibly resolves the discrepancy between the Kosterlitz-Thouless theory and previous computer experiments of atomistic systems.