Electronic structures of Ag/Ge(0 0 1) surfaces
- 作者：Kan Nakatsuji ; Yasumasa Takagi ; Masamichi Yamada ; Yoshitaka Naitoh and Fumio Komori
- 关键词：Silver ; Germanium ; Surface restructuring ; Growth mechanism ; Photoemission spectroscopy
- 刊名：Surface Science
- 出版年：2005
- 期刊代码：104_00396028
- 类别：ch
- 出版时间：2005
- 卷：591
- 期：1-3
- 页码：108-116
- 文件大小：234 K
摘要
The electronic states of Ag deposited Ge(0 0 1) surfaces at 100 K and their changes after the annealing at room temperature were investigated by using low-temperature angle-resolved photoelectron spectroscopy. Below 1 mono-layer of Ag, the surface did not show any metallic behaviors both at 130 K and after the annealing at room temperature. At 130 K, the Ag atoms adsorb as Ag ad-dimer at valley bridge site between the adjacent substrate dimer rows without breaking the Ge dimer structure. After the annealing at room temperature, the signal from the Ge dimer back-bond is significantly modified indicating changes in the dimer structure. All these findings are consistent with the previous observations by scanning tunneling microscopy: thermal diffusion and clustering of initially adsorbed Ag aggregates below 180 K; transformation of internal structure of Ag islands by further annealing above 240 K. The present study strongly supports the transformation as a restructuring process between Ag and Ge atoms at the interface.