Large-scale phase-field simulation of three-dimensional isotropic grain growth in polycrystalline thin films

In this study, assuming an ideal system free from thermal grooving and anisotropy in grain boundary properties, we analyze thin-film grain growth via three-dimensional (3D) phase-field simulations with approximately one million initial grains. The large-scale simulations accelerated by multiple graphics processing units allow for the reliable statistical investigation of grain growth behaviors in films with various thickness. Over the transition from 3D to two-dimensional (2D) growth modes, variations in the averages and distributions of grain sizes are quantified and compared for different regions of the films. Furthermore, we propose a comprehensive scaling law of thin-film grain growth, by which the 3D-2D transition behaviors and grain growth kinetics can be described in a unified manner independent of film thickness.