Molecular Dynamics Simulations of 2d Size-Polydisperse Fluid Close to the Freezing Transition

摘要

The effect of particle size-polydispersity on the static equilibrium properties of a model 2d-fluid is studied considering two types of size-distributions, namely, Gaussian (G) and uniform (U) using computer simulations. In this study, constant NPT molecular dynamics simulations is performed and the results are compared with that of the corresponding size-monodisperse fluid. In particular, the effect of size-disparity on the liquid-solid transition, local and global particle ordering around the freezing/melting transition is investigated. It is found that the transition temperature (T~*) is elevated by the introduction of size polydispersity in the system. The value of global hexatic order parameter for polydisperse systems is far below 50%, while it is around 80% for size-monodisperse fluid at the respective T~*.