Shape Evolution by Surface Diffusion and Surface Attachment Limited Kinetics on Completely Faceted Surfaces

W. Craig Carter
National Institute of Standards and Technology
Gaithersburg, Maryland

The governing equations were derived for two limiting cases of area preserving evolution of completely faceted interfaces in two dimensions: surface diffusion(SD) and surface attachment limited kinetics (SALK). Computational algorithms were developed to calculate the evolution for arbitrary initial data and polygonal Wulff shapes. Calculations for particular initial data of each type of diffusional mechanism were performed and served to distinguish the character of the flow as well as illustrate the nature of crystalline interface motion. Surface diffusion had a proximity effect which made the system appear to try to develop local approximations to the global Wulff shape, while no such effect was apparent in SALK. The effect was that a crystalline analog to convexity was not preserved in SD and was preserved during SALK.