| Summary: | 碩士 === 國立中央大學 === 物理學系 === 104 === In this study, the Ag thin films of different thickness were grown on freshly cleaved mica. We investigated these thin films with scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and X-ray photoemission spectroscopy (XPS).
In the experimental results of 400 nm, 200 nm and 100 nm sample, clear (1×1) LEED pattern was observed after the sample was cleaned by sputtering and annealing. It indicates that the surface of the Ag films are highly ordered with only one orientation, resembling to the Ag(111) single crystal. In the STM results, 400-nm-wide flat terrace was obtained after sputtering and annealing the surface. We also investigated the change of the surface caused by sputtering and annealing. In order to determine the orientation of surface Ag atoms, we deposited Bi on the surface. We observed aligned (√3×√3)R30° reconstruction at different regions on the surface, which means only one orientation on the surface. In the results of Si deposition experiments, the (4×4) and (√13×√13)R13.9° reconstructions were observed. This is the same as the results of the Si deposition on Ag(111) single crystal. Our results demonstrate that the surface of the Ag/mica thin film indeed possesses the surface characteristics of the Ag(111) single crystal.
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