氯原子在Ag低指数面上的吸附位和吸附态

应用原子和表面簇合物相互作用的5参数Morse势方法(简称5-MP)对Cl-Ag低指数表面体系进行了研究, 并获得了全部的临界点特性, 如吸附位、吸附几何、结合能、正则振动等. 计算结果表明: 在Ag(100)面上, Cl原子吸附在四重洞位; 在Ag(111)面上, Cl吸附在三重洞位; 尽管第一与第二周期原子在(110)面上的稳定吸附态大都为赝式三重位和长桥位, 但在Ag(110)面上, 四重洞位是氯原子的稳定吸附态. 理论分析结果和实验推测结果符合得很好. 理论结果给出Cl原子在Ag表面的吸附结合能和表面簇合物的粗糙度有关, 结合能从小到大的顺序为(111)＜(100)＜(110).

Adsorption and Vibration for Cl Atom on Ag Low-index Surfaces

The 5-parameter Morse potential (5-MP) of the interaction between Cl atom and Ag surface has been constructed. The adsorption and diffusion of Cl on Ag low index-surfaces were investigated with 5-MP in detail. All critical characteristics of the system have been obtained, such as adsorption site, adsorption geometry, binding energy, eigenvalues for vibration, etc. The calculated results show that Cl atom is located in the fourfold hollow site of the intact Ag(100) surface. Although quasi-3-fold site and long-bridge site is a stable adsorption site on Ag(110) surface for the first and second period atoms, the fourfold-hollow becomes the most stable adsorption site for Cl on Ag(110) and Cl atom tends to occupy 3-fold site on Ag(111) sur-face. For the Cl-Ag surface adsorption system, the surface binding energy of Cl atom is relevant to the coarse degree of cluster surface with the binding energy ordered as (111)<(100)<(110).