Scanning Tunneling Microscopy Study of the Relaxation Mechanism of a Au(100) Nanostructure

The three-dimensional shape relaxation of gold nanostructures was studied by scanning tunneling microscopy in real time and at ambient conditions. The nanostructures were fabricated on a Au(100) single crystal by a two step-process: electrochemical etching to produced a rough surface, followed by thermal annealing. The nanostructures can be described as mounds having small semicircular facets that shrink in time, peeling away layer by layer as a result of the sudden temperature change and evolving towards thermodynamic equilibrium. A model developed by Uwaha is used to describe the dynamic evolution of the peeling layers, where good agreement was found despite the presence of adsorbates due to ambient exposure.

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Self-Assembled InAs Islands on (AI,Ga)As, an In Situ Scanning Tunneling Microscopy Study

MRS Proceedings ◽

10.1557/proc-571-165 ◽

1999 ◽

Vol 571 ◽

Author(s):

P. Ballet ◽

J.B. Smathers ◽

G.J. Salamo

Keyword(s):

Scanning Tunneling Microscopy ◽

Molecular Beam ◽

Three Dimensional ◽

Microscopy Study ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Self Organized ◽

Scanning Tunneling Microscopy Study ◽

Island Density

ABSTRACTWe report an in-situ molecular beam epitaxy – scanning tunneling microscopy study of three dimensional (3D) self organized InAs islands on (AI,Ga)As surfaces. The influence of the presence of Al atoms on the roughness of the starting surface and on the island density is shown by investigating several Al compositions. We emphasize the case of InAs/AlAs and point out the major differences between this system and the widely studied InAs/GaAs system.

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Scanning Tunneling Microscopy Study of α,ω-Dihexylsexithiophene Adlayers on Au(111): A Chiral Separation Induced by a Surface

Microscopy and Microanalysis ◽

10.1017/s1431927612000566 ◽

2012 ◽

Vol 18 (4) ◽

pp. 885-891 ◽

Cited By ~ 1

Author(s):

Yonghai Song ◽

Yu Wang ◽

Lingli Wan ◽

Shuhong Ye ◽

Haoqing Hou ◽

...

Keyword(s):

Scanning Tunneling Microscopy ◽

Self Assembly ◽

Room Temperature ◽

Three Dimensional ◽

Microscopy Study ◽

Molecular Structures ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Left Handed ◽

Bulk Structure

AbstractThe self-assembly of α,ω-dihexylsexithiophene molecules on an Au(111) surface was examined by using scanning tunneling microscopy at room temperature, revealing the internal molecular structures of the sexithiophene backbones and the hexyl side chains. The α,ω-dihexylsexithiophene formed a large and well-ordered monolayer in which the molecule lay flatly on the Au(111) surface and was separated into two chiral domains. A detailed observation reveals that the admolecules were packed in one lamellae with their molecular axis aligned along the main axis of the Au(111) substrate with their hexyl chains deviated from ⟨110⟩ direction of the Au(111) substrate by 12 ± 0.5°. In contrast to the behavior in the three-dimensional bulk structure, flat-lying adsorption introduced molecular chirality: right- and left-handed molecules separate into domains of two different orientations, which are mirror symmetric with respect to the ⟨121⟩ direction of the Au(111) substrate. Details of the adlayer structure and the chiral self-assembly were discussed here.

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