1. New structural model for Na6Si3 surface magic cluster on the Si(111)-7×7 surface.
- Author
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Chou, Jyh-Pin, Hsing, Cheng-Rong, Chen, Jen-Chang, Lee, Jing-Yee, and Wei, Ching-Ming
- Subjects
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STRUCTURAL frame models , *ADSORPTION (Chemistry) , *SODIUM , *HEXAGONS , *SCIENTIFIC observation , *ADATOMS , *SCANNING tunneling microscopy - Abstract
Abstract: The adsorption of Na atoms on the Si(111)-7×7 surface is studied using first-principles calculations. Compared to the Triangle-Trimer model reported previously, we propose a more stable and robust Na6Si3 Hexagon-Trimer model which has six Na atoms with hexagon shape and three Si edge adatoms moving inward to form a trimer. The total energy of Hexagon-Trimer model is 0.252eV lower than that of Triangle-Trimer model and 0.552eV lower than that of Hexagon model. The simulated STM images of Hexagon-Trimer model are in good agreement with experimental STM observations. The most probable formation process of Hexagon-Trimer model is analyzed. The reaction is catalyzed by a Na atom and the energy barrier is reduced from 0.89 to 0.44eV. These results have provided a complete picture for the formation mechanism of Na6Si3 surface magic clusters on the Si(111)-7×7 surface. [Copyright &y& Elsevier]
- Published
- 2013
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