论文标题
与扩散大量运输的界面碰撞
Interface collisions with diffusive mass transport
论文作者
论文摘要
我们报告了一个线性Langevin模型，该模型描述了两个接口的粗糙度的演变，这些界面彼此相互移动并与扩散场耦合。该模型旨在描述生长过程中两个二维物质域之间的间隙以及随后形成粗糙的晶界。我们假设沉积发生在两个域之间的缝隙中，并且生长单元扩散并可能附着在域的边缘上。这些单元也可以从其他地方的边缘，分散和重新连接。对于缓慢的生长，边缘粗糙度单调增加，然后以一些平衡值饱和。为了快速生长，粗糙度在两个接口之间的碰撞之前表现出最大值，其次是最小值。粗糙度的峰值可以由统计波动或边缘不稳定性主导。获得了三个方案的相图：缓慢的生长，没有峰值，峰值由统计波动支配，而峰值则以不稳定性为主。这些结果重现了动力学蒙特卡洛模拟中观察到的主要特征。
We report on a linear Langevin model that describes the evolution of the roughness of two interfaces that move towards each other and are coupled by a diffusion field. This model aims at describing the closing of the gap between two two-dimensional material domains during growth, and the subsequent formation of a rough grain boundary. We assume that deposition occurs in the gap between the two domains and that the growth units diffuse and may attach to the edges of the domains. These units can also detach from edges, diffuse, and re-attach elsewhere. For slow growth, the edge roughness increases monotonously and then saturates at some equilibrium value. For fast growth, the roughness exhibits a maximum just before the collision between the two interfaces, which is followed by a minimum. The peak of the roughness can be dominated by statistical fluctuations or by edge instabilities. A phase diagram with three regimes is obtained: slow growth without peak, peak dominated by statistical fluctuations, and peak dominated by instabilities. These results reproduce the main features observed in Kinetic Monte Carlo simulations.
