Физика Низких Температур: Том 27, Выпуск 9-10 (Сентябрь 2001), c. 1092-1109    ( к оглавлению , назад )

Shell effects in alkali metal nanowires

A. I. Yanson3

Present address: Dept. of Physics, 510 Clark Hall, Cornell University, Ithaca, NY 14853

I. K. Yanson3

B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences 47 Lenin ave., 61103, Kharkov, Ukraine

J. M. van Ruitenbeek

3Kamerlingh Onnes Laboratorium, Leiden University, PO Box 9504, NL-2300 RA Leiden, The Netherlands

Received July 3, 2001

Аннотация

After making a cold weld by pressing two clean metal surfaces together, and gradually separating the two pieces, a metallic nanowire is formed, which is progressively thinning down to a single atom before the contact is lost. We show evidence that the radii of such nanowires are influenced by electronic shell filling effects, in analogy to electronic shell structure in metal clusters. A modulation of the shell effect, known as supershell structure, is clearly observed. For sodium and potassium at larger diameters there is a crossover to crystalline facets with shell-closings corresponding to the completion of an additional atomic layer. We conclude that a complete analogy exists between shell structure in metallic clusters and nanowires.

PACS:
73.20.Dx -
73.40.Jn - Metal-to-metal contacts