Flattenning of Grooves: From Step Dynamics to Continuum Theory
Flattenning of Grooves: From Step Dynamics to Continuum Theory
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凹槽的扁平化：从阶跃动力学到连续介质理论
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
Lei
中科院分区：
文献类型：
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作者：
Lei
晶体通常与其独特的多面体形状有关。其光滑，闪亮的方面提供了一个恒定的魅力来源，以古代。干旱的现代生物一样。显微镜的进步并没有给这个神话带来一点污点：有趣的表面结构被发现到原子水平，无论是表面重建，表面波纹和酒窝，还是雪花状的分形。我们看到的大多数表面结构都是非平衡模式。这是因为晶体表面的弛豫动力学通常很慢，除非非常接近熔点。此外，在粗化温度TR下，预期松弛行为发生质的变化。TR的实际值不仅取决于所处理的物质，而且还取决于晶体学。表面的方向。对于给定的材料，低米勒指数表面的TR最高。并且对于高米勒指数表面（称为邻近表面）变得非常小。Mullins（1963）回顾了近平衡表面弛豫的经典理论。在这个理论中，表面轮廓h（x）的演化是由过剩化学势μ（x）~ -Δ 2 h的变化所驱动的。(1)实际的松弛率取决于大规模运输操作的方式。三种基本模式是：
Crystals are often associated with their unique polyhedral shapes. Their smooth, shining facets provide a constant source of fascination to ancient. arid modern beings alike. Advances in microscopy have not, tainted the myth a bit: interesting surface structures are found down to the atomic level, be it surface reconstruction, surface ripples and dimples, or snow–flakish fractals... Most surface structures we see are nonequilibrium patterns. This is brcause the relaxational dynamics of a crystal surface is usually quite slow unless one is very close to the melting point. In addition, a qualitative change in the relaxation behavior is expected at the roughening temperature TR. The actual value of TR depends not only on the substance one is dealing with, but, also on the crystallographic. orientation of the surface. For a given material, TR is highest for low Miller index surfaces. and becomes vanishingly small for high Miller index surfaces (known as vicinals). ‘The classical theory of near-equilibrium surface relaxation was reviewed by Mullins (1963). In this theory, evolution of the surface profile h(x) is driven by variations of an excess chemical potential μ(x) ~ –∇2h. (1) The actual rate of relaxation dependsonthe mode of masstransport operative. The three basic modes are: