Meca Esteban, Shenoy Vivek B, Lowengrub John
Department of Mathematics, University of California, Irvine, California 92697-3875, USA.
Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Nov;88(5):052409. doi: 10.1103/PhysRevE.88.052409. Epub 2013 Nov 27.
In the present article, we introduce a phase-field model for thin-film growth with anisotropic step energy, attachment kinetics, and diffusion, with second-order (thin-interface) corrections. We are mainly interested in the limit in which kinetic anisotropy dominates, and hence we study how the expected shape of a crystallite, which in the long-time limit is the kinetic Wulff shape, is modified by anisotropic diffusion. We present results that prove that anisotropic diffusion plays an important, counterintuitive role in the evolving crystal shape, and we add second-order corrections to the model that provide a significant increase in accuracy for small supersaturations. We also study the effect of different crystal symmetries and discuss the influence of the deposition rate.
在本文中，我们引入了一个用于薄膜生长的相场模型，该模型考虑了各向异性台阶能、附着动力学和扩散，并包含二阶（薄界面）修正。我们主要关注动力学各向异性占主导的极限情况，因此研究了微晶的预期形状（在长时间极限下即动力学伍尔夫形状）如何因各向异性扩散而改变。我们给出的结果证明，各向异性扩散在晶体形状演变中起着重要且违反直觉的作用，并且我们对模型添加了二阶修正，这在小过饱和度情况下能显著提高精度。我们还研究了不同晶体对称性的影响，并讨论了沉积速率的影响。
