摘要
选取三层原子簇模型模拟Ag(110)表面，采用量子化学的电子密度泛函方法(DFT)研究了氧原子吸附在Ag(110)表面而引起银表面的多种重构现象。通过计算体系结合能优化得到吸附后体系的表面几何构型，并给出了相关的电离能、电子跃迁能。计算表明：氧原子吸附在银原子的长桥位上，位于银表面之上约0.4处，氧原子的吸附引起银原子表面强烈弛豫。第一、二层银原子间距扩张；第二、三层银原子间距收缩。由于氧原子的吸附，第一层银原子出现丢失行现象，第二层银原子出现两两成对现象，而第三层银原子出现弯曲现象。
Using a three-layer cluster model, we calculated the bonding energy of the Ag(110)-O(2×1) phase by DFT method. O atoms are found to occupy the long-bridge site 0.04 above the silver atoms. At the same time, we confirmed the missing-row reconstruction with the formation of the -Ag-O-Ag- chains along the <110> direction. The top three layers of Ag surface are strongly relaxed, with an expansion of the first-to-second layer distance, and a contraction of the second-to-third interlayer spacing, compared to the ideal silver crystal spacing, respectively. A pairing effect of the second-layer Ag atoms and a slightly buckling effect of the third-layer Ag atoms are also found. The results are well consistent with the experimental and other theoretical results.
基金
国家自然科学基金!(298783043)
关键词
银原子簇
氧原子
吸附
表面驰豫
重构
DFT
Silver cluster, Atomic adsorption, Surface relaxation and reconstruction, DFT methl
