用弹性多位相互作用模拟Cu（001）表面氮c（2x2）岛的尺寸
Modelling the size of Nitrogen c(2x2) islands on Cu(001) with elastic multisite interactions
摘要：
采用扩展的吸附原子弹性本征矢方法，模拟了Cu（001）表面氮原子c（2x2）岛.被认为是吸附原子单体或二聚体之间的振荡相互作用。吸附原子的吸引力对相互作用能够描述聚集，但不能解释岛的大小。然而，如果适当调整相互作用参数，则由二聚体产生的多位点相互作用可以解释岛的大小。当排斥性单体相互作用被吸引性单体-二聚体相互作用平衡时，形成有限大小的岛。一个简单的最近邻吸引和s-3排斥模型被用作相互作用参数搜索的例子。先前的实验研究已经表明，在低覆盖区域中，氮原子聚集成具有c（2x2）结构的约5 nm X 5 nm大小的孤立的方形岛。随着覆盖率的增加，这些岛形成规则的图案，但不接触低于约0.4单层。已有的实验和计算表明，方形岛状结构具有明显的弹性效应。分析了氮岛内不同的吸附原子结构，二聚体台阶模型能够再现实验发现的岛尺寸。该模型需要由氮吸附原子形成的二聚体之间的分子键。该模型也被用来计算岛屿之间的弹性相互作用，并检查它对实验发现的岛屿模式。讨论了该模型的缺点和局限性，并提出了有待解决的问题。
英文摘要：
An extended elastic eigenvector approach for adatom interactions is applied to model Nitrogen c(2x2) Atom islands on Cu(001). Oscillating interactions between adatom monomers or dimers are considered. Attractive pair interactions of adatoms are able to describe agglomeration but fail to explain the size of islands. Multisite interactions created by dimers, however, can explain the size of islands if an interaction parameter is adjusted properly. Finite size islands are formed when repulsive monomer interactions are balanced by attractive monomer-dimer interactions. A simple model of nearest neighbour attraction and s-3 repulsion is used as an example for the interaction parameter search. Previous experimental studies have shown that in the low coverage region Nitrogen atoms agglomerate to isolated square islands of about 5 nm x 5 nm size with a c(2x2) structure. With increasing coverage those islands form regular patterns but do not touch below about 0.4 monolayers. Previous experiments and calculations have shown that the square island pattern show significant elastic effects. Different adatom structures within the Nitrogen islands have been analyzed, a dimer step model is able to reproduce the experimentally found island size. This model requires a molecular bond between dimers formed by Nitrogen adatoms. The model is also used to compute elastic interactions between islands and to check it against the experimentally found island pattern. Shortcomings and limitations of the model are discussed and open questions are formulated.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
