Effect of boundary grooving on grain growth by Potts model simulations

Grain growth in thin films is a technologically important and scientifically fascinating topic: As the grain size influences many mechanical and optical properties of a material, any change in the grain structure and therewith in the grain size changes also the materials properties. There are many factors influencing coarsening of the microstructure such as grain boundary properties or the presence of particles; additionally the film thickness becomes rather important. It has been observed that when the grain size reaches the magnitude of the layer thickness, coarsening slows down and may even stagnate. For thin films, surface effects such as grain boundary grooving become important. In general, grooves are totally left out of implementations in the standard Potts model. In the current investigation, we introduce grain boundary grooves in the Potts model as physical entities. In the analysis, we show how the mere presence of such grooves reduces the driving force of grain boundary migration at the surface tremendously at any stage of coarsening.