Water monomer and dimer on Cu(110) studied using a scanning tunneling microscope

Abstract

The authors studied the structure and dynamics of water monomer and dimer on Cu(110) by using a scanning tunneling microscope (STM) and density-functional theory (DFT). The monomer adsorbs on top of a Cu atom and thermally hops along the atomic row at 6 K. The hopping motion is also induced via inelastic electron tunneling process. The dimer consists of hydrogen-bond donor and acceptor molecules, that were observed to dynamically exchange their roles via hydrogen-bond rearrangement. The interchange motion was suppressed upon substitution with heavy water, suggesting that the process involves quantum tunneling. © 2008 The Surface Science Society of Japan.