Formation of monomer to tetramer Ag nanodots in a vanadium oxide nanomesh on Pd(111)

Abstract

The size and structure of silver (Ag) nanodots on a vanadium oxide nanomesh on Pd(111) were examined by a combination of scanning tunneling microscopy, x-ray photoelectron spectroscopy, and ab initio calculations based on density functional theory. At the very beginning of the Ag deposition, a single Ag atom filled with the vanadium oxide nanomesh, forming a monomer Ag nanodot. As the Ag coverage increased, dimer, trimer, and tetramer Ag nanodots were formed. Locally, some of the Ag atoms formed Ag clusters on top of the vanadium oxide nanomesh. The silver atoms deposited on the nanohole did not easily migrate beyond the edge of the vanadium oxide nanomesh at room temperature, resulting in the formation of local nanodots composed of multiple Ag atoms instead of uniform monomer nanodots on the nanoholes.