Scanning tunneling microscopy at multiple voltage biases of stable “ring-like” Ag clusters on Si(111)–(7×7)

Abstract

Since more than twenty years it is known that deposition of Ag onto Si(111)-(7 × 7) leads under certain conditions to the formation of so-called "ring-like" clusters, that are particularly stable among small clusters. In order to resolve their still unknown atomic structure, we performed voltage dependent scanning tunneling microscopy (STM) measurements providing interesting information about the electronic properties of clusters which are linked with their atomic structure. Based on a structural model of Au cluster on Si(111)-(7 × 7) and our STM images, we propose an atomic arrangement for the two most stable Ag "ring-like" clusters.

Quasi one-dimensional Ag nanostructures on Si(331)–(12 × 1)

“…A similar effect occurs with deposition of Ag or Au on the Si(5 5 12) surface [15]. Typical other limitations include, for example, coalescence of the deposited atoms [14] and the formation of another surface reconstruction with annealing [16]. …”

“…One expects [14] a moderate annealing to increase the size of "sawtooth" zones while eliminating small irregular structures, thanks to the difference in thermal stability. The mechanism behind this is the increase of surface atoms mobility at an increased temperature.…”