2018/06/21 by Jiang, Wei, Zhao, Quan, Qian, Tiezheng +2 · 1 citation
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Soft Condensed Matter (cond-mat.soft)
paper · doi:10.48550/arxiv.1806.08272
In this paper, we consider the capillarity-driven evolution of a solid toroidal island on a flat rigid substrate, where mass transport is controlled by surface diffusion. This problem is representative of the geometrical complexity associated with the solid-state dewetting of thin films on substrates. We apply Onsager's variational principle to develop a general approach for describing surface diffusion-controlled problems. Based on this approach, we derive a simple, reduced-order model and obtain an analytical expression for the rate of island shrinking and validate this prediction by numerical simulations based on a full, sharp-interface model. We find that the rate of island shrinking is proportional to the material constants B and the surface energy density γ0, and is inversely proportional to the island volume V0. This approach represents a general tool for modeling interface diffusion-controlled morphology evolution.