The striped phases of ethylthiolate monolayers on the Au(111) surface: A scanning tunneling microscopy study

Abstract

Striped phases of ethylthiolate monolayers, corresponding to surface coverage in between 0.2 ML and 0.27 ML, were studied using high-resolution scanning tunneling microscopy. Striped phases consist of rows of Au-adatom-diethythiolate (AAD) aligned along the [112] direction. In the perpendicular [110] direction, the AAD rows adjust their spacing according to the surface coverage. A (5√3 × √3)-R30° striped phase with 0.27 ML thiolate and a (6√3 × √3)-R30° striped phase with 0.23 ML thiolate, both with long-range order, are found. A localized (5 × √3)-rect. phase is also found as a minority phase embedded in the 5√3 × √3)-R30° phase. This (5 × √3)-rect. phase can be constructed using di-Au-adatom-tri-thiolate species.

Diffusion of Au(CH3S)2 on Au(111) Observed with the Scanning Tunneling Microscope

“…Au(CH3S)2 molecules have a tendency to form rows along the [112 ̅ ] direction for a broad range of coverages due to an attractive interaction between nearest neighbor molecules 6,13 . This row structure is rather common and observed for alkyl-thiolates with different alkane lengths 18,19 . An Au(CH3S)2 molecule can break off from the end of a Au(CH3S)2 row in a thermally activated process.…”

Surface-induced symmetry reduction in molecular switching: asymmetric cis–trans switching of CH3S-Au-SCH3on Au(111)

“…By acquiring images with different bias voltages from -1 V to 1 V with the tunnel current fixed, we found that switching is independent of the bias polarity, but becomes more effective as the bias gets lower corresponding to smaller tip-molecule distances. From experiments with Audiethylthiolate, we know that thermally-induced cis-trans isomerization does not take place even at room temperature [23] . This implies an activation barrier higher than 25 meV.…”

Growth of Two-Dimensional C60 Nanoclusters within a Propylthiolate Matrix

“…The distance between neighboring two rows is coverage dependent. 49,52,53 One striped phase can change into another when the molecular coverage changes. Also shown in Fig.…”