| タイトル | Competing Classical and Quantum Effects in Shape Relaxation of a Metallic Nanostructure |
| 著者（英） | Biegel, Bryan; Okamoto, Hiroshi; Chen, Dongmin; Yamada, Toshishi |
| 著者所属（英） | Computer Sciences Corp.; NASA Ames Research Center |
| 発行日 | 2003-01-01 |
| 言語 | eng |
| 内容記述 | We demonstrate for the first time that the quantum size effect (QSE) plays a competing role along side the classical thermodynamic effect in the shape relaxation of a small metallic island. Together, these effects transforms a lead(Pb) island grown on Si(111) substrate from its initially flattop faceted morphology to a peculiar ring-shape island, a process catalysed by the tip electric field of a scanning tunnelling microscope (STM). We shall show for the first time how QSE affects the relaxation process dynamically. In particular, it leads to a novel strip-flow growth and double-step growth on selective strips of a plateau inside the ring, defined by the substrate steps more than 60?0?3 below. It appears that atoms diffusing on the plateau can clearly (sub i)(deg)sense(sub i)+/- the quantized energy states inside the island and have preferentially attached to regions that further reduces the surface energy as a result of the QSE, limiting its own growth and stabilizing the ring shape. The mechanism proposed here offers a sound explanation for ring shape metal and semiconductor islands observed in other systems as well. |
| NASA分類 | Solid-State Physics |
| 権利 | No Copyright |
|
