Identification of an AgS2 Complex on Ag(110)

Peter M Spurgeon,Patricia A Thiel,Yousoo Kim,Junepyo Oh,Da-Jiang Liu

doi:10.1038/s41598-019-56275-4

Peter M Spurgeon, Patricia A Thiel + Show 3 more

Open Access

https://doi.org/10.1038/s41598-019-56275-4

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Abstract

Adsorbed sulfur has been investigated on the Ag(110) surface at two different coverages, 0.02 and 0.25 monolayers. At the lower coverage, only sulfur adatoms are present. At the higher coverage, there are additional bright features which we identify as linear, independent AgS2 complexes. This identification is based upon density functional theory (DFT) and its comparison with experimental observations including bias dependence and separation between complexes. DFT also predicts the absence of AgS2 complexes at low coverage, and the development of AgS2 complexes around a coverage of 0.25 monolayers of sulfur, as is experimentally observed. To our knowledge, this is the first example of an isolated linear sulfur-metal-sulfur complex.

Highlights

Adsorbed sulfur has been investigated on the Ag(110) surface at two different coverages, 0.02 and 0.25 monolayers
Adsorbed sulfur has been explored on Ag(110) surface at two different coverages, 0.02 and 0.25 ML
Sulfur adatoms exhibit local ordering in the form of short chains with sulfur adatoms separated by 2a1, or small local p(2 × 2)

Summary

Introduction

Adsorbed sulfur has been investigated on the Ag(110) surface at two different coverages, 0.02 and 0.25 monolayers. For the coinage metal surfaces, metal-sulfur complexes were observed with low-temperature STM on Cu(111)[28], Ag(111)[29], and Au(100)[30], with structures proposed for each of the complexes. No detailed structures of these clusters have been proposed and the clusters were imaged at 77 K, leading to the clusters appearing streaky or fuzzy in STM images due to the clusters being semi-mobile on the surface In another related system, it has been demonstrated using low-temperature STM, that oxygen on Ag(110) can produce a variety of features[32,33]. It was proposed that the embedded complex can detach from its lateral surroundings and become “free,” aiding in the creation of surface vacancies These “free” AgO2 complexes may serve as the building blocks of the Ag(110)-O-(2 × 1) added row reconstruction[33].

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