Speaker
Description
We present a multi-phase field model to study break-up and droplet formation in thin metal films. This model represents individual metal grains as distinct phase-field variables and captures the effects of coarsening and surface diffusion [1]. By coupling the phase-field model to a chemical potential field through the grand potential formulation, we develop a robust framework for simulating dewetting phenomena. Our work investigates the role of interfacial energy, which can exhibit significant spatial variations. These are caused by a variation in the relative crystallographic orientation of the film and substrate, together with anisotropic properties of one of the components of the system. The inhomogeneity of interfacial energy has a significant impact on grain coarsening rates, droplet formation and the overall stability of the thin film. We systematically analyse how variations in interfacial energy inhomogeneity affect these processes, revealing critical links between material properties and film behaviour. The model is applied to thin nickel films commonly used in solid oxide fuel cells, where dewetting can adversely affect performance by reducing electrical conductivity [2]. To validate our results, we collaborate with experimental colleagues by comparing our simulations with experimental observations of nickel film dewetting. This combined approach of modelling and laboratory experiments provides a deeper understanding of dewetting dynamics and offers processing pathways to optimise thin film performance in technological applications.
