Application of Onsager's variational principle to the dynamics of a solid toroidal island on a substrate. (15th January 2019)

• Record Type: Journal Article
• Authors: Jiang, Wei; Zhao, Quan; Qian, Tiezheng; Srolovitz, David J.; Bao, Weizhu
• Is Part Of: Acta materialia. Volume 163(2019)
• Page Start: 154
• Page End: 160
• Publication Date: 2019-01-15
• Subjects: Solid-state dewetting -- Onsager's variational principle -- Surface diffusion -- Shrinking instability -- Moving contact line; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2018.10.004
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: 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 γ 0, and is inversely proportional to the island volume V 0 . This approach represents a general tool for modeling interface diffusion-controlled morphology evolution. Graphical abstract: Image 1