Simulation of Kinetically Limited Nucleation and Growth at Monatomic Step Edges
Simulation of Kinetically Limited Nucleation and Growth at Monatomic Step Edges
复制标题
单原子阶梯边缘动力学限制成核和生长的模拟
DOI：
10.1149/1.2746569
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
R. Alkire
中科院分区：
文献类型：
--
作者：
R. Stephens;R. Alkire
用动力学蒙特卡罗(KMC)数值方法研究了动力学控制的电极成核和生长的初始阶段。模拟了由金属离子组成的原始体系的沉积、表面扩散、形核和生长，该体系位于面心立方(FeE)表面附近，该表面最初由一系列平行的单原子阶梯边组成。模拟是用原子尺度的固体对固体KMC算法进行的，其中沉积的原子占据了FeE晶格的位置。对同一金属衬底上的金属沉积进行了一系列模拟。根据一个无量纲量A来表征结果，该量表示表面扩散速率与沉积速率的比率。发现当A值较大时，沉积在单原子台阶边缘生长，而当A值较小时，台阶边缘对岛的形核没有影响。对在异质衬底上的沉积进行了第二系列的模拟。探索了与各种系统参数组合相关的生长模式。
A kinetic Monte Carlo (KMC) numerical approach was used to investigate initial stages of kinetically controlled nucleation and growth on electrodes. Deposition, surface diffusion, nucleation, and growth were simulated for a pristine system consisting of metal ions in solution adjacent to a face-centered-cubic (fee) surface that is initially configured with a series of parallel, monatomic step edges. Simulations were carried out with an atomic-scale, solid-on-solid KMC algorithm, in which the deposited atoms occupied the sites of a fee lattice. One series of simulations was carried out for metal deposition onto a substrate of the same metal. The results were characterized according to a dimensionless quantity, A, that represented the ratio of the rate of surface diffusion to the rate of deposition. It was found for large values of A that the deposit grew at the monatomic step edges, whereas for small values of A the step edges played no role in the nucleation of islands. A second series of simulations was carried out for deposition onto a foreign substrate. The growth modes associated with various combinations of system parameters was explored.