Details

Autor(en) / Beteiligte

• Ghosh, Mithun
• Yang, Ding-Shyue

Titel

Structures of self-assembled n -alkanethiols on gold by reflection high-energy electron diffraction

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2020-08, Vol.22 (30), p.17325-17335

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The structures of long-chain alkanethiols (C 18 H 37 SH) chemisorbed on an Au(111) single crystal were investigated using reflection high-energy electron diffraction (RHEED). The primary structure observed as a major species in the as-deposited films contains gold adatoms below the sulfur headgroups. Between the small ordered domains with the alkyl chains tilting toward six directions are azimuthally disorderly packed regions, with a similar average tilt of 30.2°. In contrast, a significant reduction in the coverage of gold adatoms is found in the thermally-induced phase. This superlattice is shown to contain a mixture of two sulfur arrangements, both of which exhibit a small S–S distance, and the pairing of the aliphatic chains. A microscopic picture is then given for the structural transition. These findings demonstrate how the RHEED technique may be used to resolve structures of nanometer-thick thin films with multiple orders at the interfaces.