Cu(100) (2×22)R45°-O的表面结构与电子态的密度泛函研究

用第一性原理的总能计算研究了Cu(100))面的表面结构、弛豫以及氧原子的(2×22)吸附状 态.计算给出了Cu(100) (2×22)R45°-O吸附表面的结构参数，并得到了上述结构下氧吸附 的Cu(100)表面氧原子和各层Cu原子的电子态密度.计算得到的吸附表面功函数为4.58 eV ，与清洁Cu(100)表面功函数(～4.53 eV)几乎相同.吸附氧原子与最外层铜原子之间的垂直 距离约为0.02 nm，其能带结构体现出一定的金属性，同时由于Cu-O的杂化作用在费米能以 下约6.4 eV附近出现了局域的表面态.可以认为，在Cu(100) (2×22)R45°的氧吸附表面结 构下，吸附氧原子和衬底之间的结合主要来源于表面最外层铜原子与氧原子的相互作用. 关键词： Cu(100)(2×22)R45°-O表面 缺列再构 表面电子态

Density functional theory study on the atomic structure and electronic states of Cu(100) (2×22)R45°-O surface

The surface structure, relaxation, and oxygen adsorbed (2×22)R45° Cu(100) surf ace are studied by ab initio total energy calculation. The calculated atomic str ucture for the Cu(100) (2×22)R45°-O surface is quite close to the experiments except the positions of surface layer Cu atoms. The adsorbed O atoms is lying ap proximately 0.02 nm above the outermost Cu layer and produces a hybridized band and yields some localized surface states around 6.4 eV below E_F. The calculated work function for studied oxygen adsorbed surface phase is 4.58 eV, w hich is close to that of clear Cu(100) surface (～4.53 eV). It is concluded that the bonding between adsorbate and substrate copper atoms is approximately limit ed to the first surface layer.