Shah Syed Islamuddin, Nandipati Giridhar, Karim Altaf, Rahman Talat S
Department of Physics and Astronomy, University of Central Florida, Orlando, FL 32816, USA.
J Phys Condens Matter. 2016 Jan 20;28(2):025001. doi: 10.1088/0953-8984/28/2/025001. Epub 2015 Dec 11.
We studied self-diffusion of small two-dimensional Ag islands, containing up to ten atoms, on the Ag(111) surface using self-learning kinetic Monte Carlo (SLKMC) simulations. Activation barriers are calculated using the semi-empirical embedded atom method (EAM) potential. We find that two- to seven-atom islands primarily diffuse via concerted translation processes with small contributions from multi-atom and single-atom processes, while eight- to ten-atom islands diffuse via single-atom processes, especially edge diffusion, corner rounding and kink detachment, along with a minimal contribution from concerted processes. For each island size, we give a detailed description of the important processes, and their activation barriers, responsible for its diffusion.
我们使用自学习动力学蒙特卡罗（SLKMC）模拟研究了在Ag(111)表面上包含多达十个原子的二维小Ag岛的自扩散。使用半经验嵌入原子方法（EAM）势计算激活势垒。我们发现，两到七个原子的岛主要通过协同平移过程扩散，多原子和单原子过程的贡献较小，而八到十个原子的岛通过单原子过程扩散，特别是边缘扩散、拐角圆滑和扭结脱离，协同过程的贡献最小。对于每个岛的尺寸，我们详细描述了导致其扩散的重要过程及其激活势垒。
