Growth and structure of gold films on a Re() surface

Abstract

We have deposited Au films in ultra-high vacuum onto a rhenium () surface in submonolayer and multilayer concentrations and studied them by means of low- andmedium-energy electron diffraction in the temperature range between 300 and 800 K. In thesubmonolayer range, Au forms several low-energy electron diffraction (LEED) phases, namely, a(1 × 3), a(1 × 4),a (1 × 5)and a (1 × 6) phase, consisting of one-dimensionally ordered Au chains in the [] direction, until the formation of a complete pseudomorphic monolayer is indicated by a(1 × 1) LEED phase. In themultilayer regime, a (1 × 8) LEED phase appears over a surprisingly wide coverage range from about two to atleast eight monolayers, which we interpret as a hexagonal uniaxially compressedreconstructed Au overlayer on pseudomorphically grown hexagonal close-packed goldlayers. In order to get access to absolute Au coverages, we have performed LEED(I,V) measurements and carried out a LEED structure determination for the(1 × 1) phase. We propose the formation of a full Au monolayer in which both the Re trough andtop-row sites are being covered by Au atoms. The data are discussed and compared withthose from previous studies on related systems.