ETSF and Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via Cozzi 53, 20125 Milano, Italy.
J Phys Condens Matter. 2011 Jan 12;23(1):015001. doi: 10.1088/0953-8984/23/1/015001. Epub 2010 Nov 26.
We present the results of density functional theory simulations of the adsorption of Pd on the Au(111) surface at low coverage. The potential energy surface for Pd adatoms is determined and found to be shallower than that related to atomic-size features observed in scanning tunneling experiments. The commonly found Pd-Pd repulsion within Au also applies in the case of adatoms on a perfect Au(111) surface interacting with surface/subsurface ones, despite the role of the latter entities in the island nucleation on the real, reconstructed surface. Alteration of the surface lattice parameter or of the stacking of Au layers, featured by the Au(111)-[Formula: see text] surface, is also modeled and found not to modify the energetics of Pd islands. The appearance of Pd monomers in simulated scanning tunneling topographies is discussed and shows an important contribution by the Au surface state in determining the relative height of surface and subsurface Pd atoms, in agreement with recent experimental findings.
我们呈现了在低覆盖度下钯在金（111）表面吸附的密度泛函理论模拟结果。确定了钯原子吸附的位能面，发现其比在扫描隧道实验中观察到的原子大小特征的相关位能面浅。在与表面/次表面相互作用的完美金（111）表面上的吸附原子中，也存在常见的钯-钯排斥，尽管在后一种实体在实际重构表面的岛核形成中起作用。由 Au(111)-[Formula: see text]表面特征的表面晶格参数或 Au 层堆积的改变也进行了建模，发现不会改变 Pd 岛的能态。讨论了模拟扫描隧道形貌中钯单体的出现，并表明 Au 表面态在确定表面和次表面 Pd 原子的相对高度方面有重要贡献，这与最近的实验结果一致。
