S在Cu(111)表面吸附的第一性原理研究  

First-principles study of the S/Cu(111) interface

作　　者：楚兴丽[1] 路战胜[1] 杨宗献[1] 

机构地区：[1]河南师范大学物理信息与工程学院,新乡453007

出　　处：《原子与分子物理学报》2011年第3期557-562,共6页Journal of Atomic and Molecular Physics

基　　金：基金项目国家自然科学基金(10674042);"河南省创新型科技人才队伍建设工程"(104200510014)

摘　　要：基于广义梯度近似的投影缀加平面波(Projector augmented wave)赝势和具有三维周期性边界条件的超晶胞模型,采用第一原理方法计算并分析了由S吸附所形成的S/Cu(111)界面体系的吸附结构、吸附能和局域电子结构,考虑了不同覆盖度(1,0.25 ML)下S在不同吸附位置的吸附特性.结果表明:S原子倾向于吸附在高对称的fcc位与hcp位;由于S的负电性而使S/Cu吸附能随覆盖度的减小而增加,与之相应,S-Cu键长随覆盖度的减小而缩短.DOS图、Bader电荷分析表明杂化主要发生在S的3p态和表面Cu原子的3d态之间,表层近邻的Cu原子向S转移的电子数随覆盖度增加而减小,这表明S与Cu(111)面有强的相互作用.The adsorption of a sulfur atom on the Cu（111） surface is studied using first principles method. Different sulfur coverage （θ） of 1,0.25ML and several adsorption geometries are considered. It is confirmed that S energetically favors the high coordination sites, i.e. fcc and hcp sites for p（1 ×1） and p （2× 2） phases. The optimized geometries are in good agreement with experimental results. S adsorption gets weaker as coverage increases and the difference in S adsorption energies among fce and hcp site becomes smaller, correspondingly, the Cu-S bond lengths are elongated. Moreover, density of states and Bader-type analysis are presented for S adatom in the hcp site. It is found that the S-Cu hybridization mostly arises between the Cu 3d states and the S electrons from the nearest neighbor Cu atoms for 3p states and the S adatoms obtain different amount of different S coverages.

关 键 词：S吸附 CU(111) 第一性原理 电子结构 

分 类 号：O485[理学—固体物理]