Effect of boundary grooving on grain growth by Potts model simulations

Abstract

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.

Growth paths in polycrystalline thin films

“…This type of specification has been applied successfully to various problems of grain growth in thin films in the past such as the investigation of texture controlled grain growth [32], of grain growth under strong temperature gradients [33] as well as of grain growth including the formation of boundary grooves [24].…”

“…Such processes can, of course, only be modeled and understood in three dimensions. Recently, Zöllner and Pantleon [24] modeled grain growth in three-dimensional films by Potts model simulations taking grain boundary grooves into account. It was shown how the mere presence of grain boundary grooves reduces the driving force of boundary migration at surfaces immensely at any stage of coarsening and can indeed lead to full stagnation.…”