Al吸附在Pt,Ir和Au的(111)面的低覆盖度研究

应用密度泛函理论，系统研究了Al原子在Pt(111)，Ir(111)和Au(111)表面的桥位、顶位、三重面心立方(fcc)洞位和六角密排(hcp)洞位这四个典型位置的吸附情况. 主要计算了三吸附体系的几何结构、平均结合能和差分电荷密度，并系统讨论了相关原子的密立根电荷布居数和投影态密度.研究发现，对于Pt(111)和Ir(111)表面，Al原子在hcp洞位最稳定，但是对于Au(111)表面，Al原子在fcc洞位最稳定.关键词：吸附密度泛函理论结合能电子结构

A low coverage investigation on Al adsorption on the(111)surface of Pt,Ir and Au

Aluminium adsorptions on Pt(111),Ir(111) and Au(111) surface are studied systematically by using the density function theory. Four highly symmetric sites, namely face-centered cubic(fcc)-hollow,hexagonal close-packed(hcp)-hollow, top and bridge sites, are adopted. We calculate atomic geometry, average binding energy and differences in electron density among the three systems. The Mulliken charge population analyses and the projected densities of states of the three systems are also discussed. It is found that the hcp-hollow site is the energetically favorable site for Pt(111)and Ir(111) surfaces, but the energetically favorable site is the fcc-hollow site for Au(111) surface.