Grain-boundary grooving by surface diffusion with strong surface energy anisotropy
Grain-boundary grooving by surface diffusion with strong surface energy anisotropy
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DOI：
10.1016/s1359-6454(03)00039-9
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发表时间：
2003-05
期刊：
影响因子：
9.4
通讯作者：
Tinghui Xin;H. Wong
中科院分区：
文献类型：
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作者：
Tinghui Xin;H. Wong
与水平自由表面相交的垂直晶界形成凹槽，以降低系统的组合表面能。凹槽随时间增长，通常用于测量表面扩散系数。这项工作研究了具有强表面能各向异性的毛细管驱动的表面扩散开槽，发现多面凹槽仍然随着时间 t（t1/4）而生长。然而，如果凹槽表面不与小平面方向交叉，则各向异性凹槽可以是平滑的。该凹槽与相应的各向同性凹槽具有相同的形状，但生长速率降低了一个取决于各向异性程度的因子。如果各向同性模型应用于平滑但各向异性的凹槽，这种减小会导致表面扩散系数出现误差。我们展示了如何纠正此错误。
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 t1/4. 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.