Grain growth in thin films by a discrete model based on pair interactions

Abstract

A discrete model is presented which predicts the curvature-driven grain growth kinetics and the grain size distribution in polycrystalline thin films. A probabilistic approach based on elementary exchanges of volume between grain pairs and a simple topological description of the system have been used to define the basic structure of the growth rate equations. In addition, the local grain-boundary curvature has been introduced in each contact between nearest neighbors instead of the average curvature adopted in mean-field models. Even in absence of inhibition right-skewed quasistationary grain-size distributions are obtained. The topological features of the polycrystal predicted by the model are compatible with the currently accepted theories and the available experimental data. The results of simulations with a constant inhibition term in the growth equation are also discussed. A comparison with experimental data and models in the literature indicates that the present formulation has a capability in predicting the shape of the grain-size distributions better than previous analytical approaches and comparable with that of numerical algorithms.