氯原子在Cu(111)表面的吸附结构和电子态  

The geometry structure and electronic states of chlorine on Cu(111) surface

作　　者：赵新新[1] 陶向明[2] 宓一鸣[1] 谭明秋[2] 

机构地区：[1]上海工程技术大学基础教学学院,上海201620 [2]浙江大学物理系,杭州310027

出　　处：《原子与分子物理学报》2009年第1期150-156,共7页Journal of Atomic and Molecular Physics

基　　金：上海市高校选拔培养优秀青年教师科研专项基金(06XPYQ44)

摘　　要：密度泛函理论(DFT)总能计算研究了不同覆盖度下氯原子在Cu(111)表面的吸附结构和表面电子态.计算结果表明,清洁Cu(111)表面自由能σ_为15.72 eV/nm^2,表面功函数φ为4.753 eV.在1/4ML和1/3ML覆盖度下,每个氯原子在Cu(111)表面fcc谷位的吸附能分别等于3.278 eV和3.284 eV.在1/2ML覆盖度下,两个紧邻氯原子分别吸附于fcc和hcp谷住,氯原子的平均吸附能为2.631 eV.在1/3ML覆盖度下,fcc和hcp两个位置氯原子的吸附能差值约为2 meV,与正入射X光驻波实验结合蒙特卡罗方法得到结果(<10 meV)基本一致.在1/4ML、1/3ML和1/2ML覆盖度下,吸附后Cu(111)表面的功函数依次为5.263 eV、5.275 eV和5.851 eV.吸附原子和衬底价轨道杂化形成的局域表面电子态位于费米能级以下约1.2 eV、3.6 eV和4.5 eV等处.吸附能和电子结构的计算结果表明,氯原子间的直接作用和表面铜原子紧邻氯原子数目是决定表面结构的两个重要因素.In this paper first principles calculation were performed on the geometric structures and adsorption properties of chlorine on Cu(111) surface at the different coverage by using USPP methods. The free surface energy of clean Cu(111) surface is about to be 15. 72 eV/nm^2, and the work function was estimated to be 4. 753 eV. At the coverage of 1/4ML, Chlorine atoms adsorbed on the fcc and hcp hollow sites. The average adsorption energy was calculated to be 3. 278 eV, comparing with 3. 284 eV and 2. 631 eV at the coverage of 1/3ML and 1/2ML respectively. In the coverage of 1/3 ML, the adsorption energy distance between fee and hep sites was predicted to be about 2 meV, which was good a-greement with the normal-incidence x-ray standing waves experiences combined with Monte Carlo simulations . The adsorption of Chlorine on Cud(111) surface yields the hybridization between surface Cu atoms and Chlorine atoms, and generates the localized surface states at-1. 2 eV,-3. 6 eV and-4. 5 eV relative to Fermi energy.

关 键 词：吸附结构 吸附能 电子态密度 功函数 

分 类 号：O641[理学—物理化学] O647[理学—化学]