Grain-boundary grooving by surface diffusion with strong surface energy anisotropy

✍ Scribed by Tinghui Xin; Harris Wong

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 178 KB
• Volume: 51
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/s1359-6454(03)00039-9

✦ Synopsis

A vertical grain boundary intercepting a horizontal free surface forms a groove to reduce the combined surface energy of the system. The groove grows with time and is commonly used for measuring surface diffusion coefficients. This work studies grooving by capillarity-driven surface diffusion with strong surface energy anisotropy and finds that faceted grooves still grow with time t as t 1/4 . However, an anisotropic groove can be smooth if the groove surface does not cross a facet orientation. The groove has the same shape as the corresponding isotropic groove, but the growth rate is reduced by a factor that depends on the degree of anisotropy. This reduction induces an error in the surface diffusion coefficient if the isotropic model is applied to a smooth, but anisotropic groove. We show how to correct for this error.