scholarly journals Strain-Relief Patterns and Kagome Lattice in Self-Assembled C60 Thin Films Grown on Cd(0001)

2021 ◽  
Vol 22 (13) ◽  
pp. 6880
Author(s):  
Zilong Wang ◽  
Minlong Tao ◽  
Daxiao Yang ◽  
Zuo Li ◽  
Mingxia Shi ◽  
...  
Keyword(s):  
Thin Films ◽  
Self Assembly ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Kagome Lattice ◽  
Tunneling Microscopy ◽  
Kagomé Lattice ◽  
Temperature Scanning ◽  
C60 Films

We report an ultra-high vacuum low-temperature scanning tunneling microscopy (STM) study of the C60 monolayer grown on Cd(0001). Individual C60 molecules adsorbed on Cd(0001) may exhibit a bright or dim contrast in STM images. When deposited at low temperatures close to 100 K, C60 thin films present a curved structure to release strain due to dominant molecule–substrate interactions. Moreover, edge dislocation appears when two different wavy structures encounter each other, which has seldomly been observed in molecular self-assembly. When growth temperature rose, we found two forms of symmetric kagome lattice superstructures, 2 × 2 and 4 × 4, at room temperature (RT) and 310 K, respectively. The results provide new insight into the growth behavior of C60 films.

scholarly journals Au(100) as a Template for Pentacene Monolayer

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2393
Author(s):  
Artur Trembułowicz ◽  
Agata Sabik ◽  
Miłosz Grodzicki
Keyword(s):  
Self Assembly ◽  
Molecular Layer ◽  
High Vacuum ◽  
Gold Surface ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Height Difference ◽  
Characteristic Features ◽  
Reconstructed Surface

The surface of quasi-hexagonal reconstructed Au(100) is used as the template for monolayer pentacene (PEN) self-assembly. The system is characterized by means of scanning tunneling microscopy at room temperature and under an ultra-high vacuum. A new modulated pattern of molecules with long molecular axes (MA) arranged along hex stripes is found. The characteristic features of the hex reconstruction are preserved herein. The assembly with MA across the hex rows leads to an unmodulated structure, where the molecular layer does not recreate the buckled hex phase. The presence of the molecules partly lifts the reconstruction—i.e., the gold hex phase is transformed into a (1×1) phase. The arrangement of PEN on the gold (1×1) structure is the same as that of the surrounding molecular domain on the reconstructed surface. The apparent height difference between phases allows for the distinction of the state of the underlying gold surface.

Packing fractal Sierpiński triangles into one-dimensional crystals via a templating method

2017 ◽  
Vol 53 (24) ◽  
pp. 3469-3472 ◽  
Author(s):  
Na Li ◽  
Gaochen Gu ◽  
Xue Zhang ◽  
Daoliang Song ◽  
Yajie Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling Microscopy ◽  
High Vacuum ◽  
Building Blocks ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Templating Method ◽  
One Dimensional ◽  
Temperature Scanning

Crystalline structures with Sierpiński triangles as building blocks were constructedviaa templating method in ultra-high vacuum and studied by low-temperature scanning tunneling microscopy.

Shape-Controlled Growth of Indium and Aluminum Nanostructures on MoS2(0001)

2008 ◽  
Vol 8 (5) ◽  
pp. 2707-2712 ◽  
Author(s):  
S. S. Kushvaha ◽  
H. Xu ◽  
H. L. Zhang ◽  
A. T. S. Wee ◽  
X.-S. Wang
Keyword(s):  
Self Assembly ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Deposition Flux ◽  
Average Height ◽  
High Flux ◽  
Molybdenum Disulphide ◽  
Tunneling Microscopy ◽  
Al Nanoparticles

The growth of indium and aluminum nanostructures on molybdenum disulphide (MoS2)(0001) substrate has been studied using scanning tunneling microscopy in ultra-high vacuum. At low coverage and room temperature (RT), mostly ultra-thin (∼1.2–2 nm) triangular In islands were observed on MoS2. With increasing coverage or high flux, large coalesced irregular islands along with triangular and round-shaped ones of increased average height were found. Triangular and round-shaped islands were obtained after annealing the RT-deposited In on MoS2 sample at 450 K. At ∼375 K, exclusively triangular In islands were observed. Al nanoparticles with diameter in 4–16 nm range were obtained after a low-flux deposited whereas ramified islands were observed in a high flux at RT. Ultra-thin (∼1.20–2 nm) Al islands and films were obtained on MoS2 after deposition at 500 K. These results demonstrate that the shape of In and Al nanostructures grown on MoS2 can be controlled in self-assembly by adjusting substrate temperature, deposition flux and amount.

Atomic Scale Engineering of SrTiO3 Single Crystal Surfaces and Bicrystal Boundaries for Epitaxial Growth of Oxide Thin Films

1997 ◽  
Vol 474 ◽  
Author(s):  
Q. D. Jiang ◽  
J. Zegenhagen
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Atomic Scale ◽  
Spiral Growth ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Annealing Procedure ◽  
Atomically Flat

ABSTRACTWe introduce a new annealing procedure to prepare well defined surfaces of SrTiO3 single crystal and bicrystal substrates. Annealing SrTiO3 (001) substrates in oxygen and then in ultra high vacuum produces a uniformly TiO2-terminated, atomically flat and ordered SrTiO3 (001) surfaces, as revealed by Auger electron spectroscopy, low energy electron diffraction, and high resolution scanning tunneling microscopy. Applying this annealing procedure to slightly off-cut (∼1.2°) SrTiO3 (001) surfaces has a strong influence on the resulting step structure. Particular annealing procedures can be used to tailor the structure and morphology of the surface and of bicrystal boundaries down to the atomic level. For example, steps of SrTiO3 (001) surfaces can be adjusted to a height of one, two, or multiple times the unit-cell size of STO (aSTO=0.3905 nm). Atomically flat SrTiO3 (001) substrates were used for deposition of SmBa2Cu3O7-δ (SBCO) thin films. The thickness (in a range from 10 nm to 200 nm) dependency of the surface morphology of SmBa2Cu3O7-δ films was investigated with UHV-STM. No spiral growth was observed. Surfaces of all films exhibit stacks of flat terraces which are frequently separated by steps, smaller than the c-axis length cSBCO of SBCO (cSBCO=1.17 nm).

Self-assembly of l-tryptophan on Cu(111) studied by low-temperature scanning tunneling microscopy

2019 ◽  
Vol 30 (12) ◽  
pp. 2355-2358 ◽  
Author(s):  
Qiang Xue ◽  
Yajie Zhang ◽  
Ruoning Li ◽  
Chao Li ◽  
Na Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling Microscopy ◽  
Self Assembly ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Temperature Scanning

scholarly journals Orientation Ordering and Chiral Superstructures in Fullerene Monolayer on Cd (0001)

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1305
Author(s):  
Yuzhi Shang ◽  
Zilong Wang ◽  
Daxiao Yang ◽  
Yaru Wang ◽  
Chaoke Ma ◽  
...  
Keyword(s):  
Thin Films ◽  
Charge Transfer ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Orientational Disorder ◽  
Temperature Scanning ◽  
Orientation Ordering ◽  
The Individual ◽  
Misorientation Angles

The structure of C60 thin films grown on Cd (0001) surface has been investigated from submonolayer to second monolayer regimes with a low-temperature scanning tunneling microscopy (STM). There are different C60 domains with various misorientation angles relative to the lattice directions of Cd (0001). In the (2√3 × 2√3) R30° domain, orientational disorder of the individual C60 molecules with either pentagon, hexagon, or 6:6 bond facing up has been observed. However, orientation ordering appeared in the R26° domain such that all the C60 molecules adopt the same orientation with the 6:6 bond facing up. In particular, complex chiral motifs composed of seven C60 molecules with clockwise or anticlockwise handedness have been observed in the R4° and R8° domains, respectively. Scanning tunneling spectroscopy (STS) measurements reveal a reduced HOMO–LOMO gap of 2.1 eV for the C60 molecules adsorbed on Cd (0001) due to the substrate screening and charge transfer from Cd to C60 molecules.

Surface stability of epitaxial SrRuO3 thin films in vacuum

2004 ◽  
Vol 19 (12) ◽  
pp. 3447-3450 ◽  
Author(s):  
J. Shin ◽  
S.V. Kalinin ◽  
H.N. Lee ◽  
H.M. Christen ◽  
R.G. Moore ◽  
...  
Keyword(s):  
Thin Films ◽  
High Vacuum ◽  
Hydrocarbon Contamination ◽  
Laser Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Surface Stability ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Deep Pits

Surface stability of nearly defect-free epitaxial SrRuO3 thin films grown by pulsed laser deposition was studied using low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), and electron spectroscopies. Even after exposure to atmosphere, surfaces exhibited distinct LEED patterns providing evidence of unusual chemical stability. Surface order disappeared after heating to 200 °C in vacuum. To investigate, SrRuO3 thin films were annealed up to 800 °C in high vacuum and examined for chemical state and topography. Formation of unit-cell deep pits and the Ru-rich particles begins at low temperatures. Hydrocarbon contamination on the surface contributes to this process.

Using a Moderate Vacuum, Hot/Cryo-Stage Equipped AFM for In-Situ Observation of α-Phase Growth In 60SN40PB Hypoeutectic Solder

1998 ◽  
Vol 4 (S2) ◽  
pp. 316-317
Author(s):  
D. N. Leonard ◽  
P.E. Russell
Keyword(s):  
Surface Science ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
In Situ Observation ◽  
Atmospheric Conditions ◽  
Tunneling Microscopy ◽  
Wide Range ◽  
Gas Environment

Atomic force microscopy (AFM) was introduced in 1984, and proved to be more versatile than scanning tunneling microscopy (STM) due to the AFM's capabilities to scan non-conductive samples under atmospheric conditions and achieve atomic resolution. Ultra high vacuum (UHV) AFM has been used in surface science applications when control of oxidation and corrosion of a sample's surface are required. Expensive equipment and time consuming sample exchanges are two drawbacks of the UHV AFM system that limit its use. Until recently, no hot/cryo-stage, moderate vacuum, controlled gas environment AFM was commonly available.We have demonstrated that phase transformations are easily observable in metal alloys and polymers with the use of a moderate vacuum AFM that has in-situ heating/cooling capabilities and quick (within minutes) sample exchange times. This talk will describe the results of experiments involving a wide range of samples designed to make use of the full capabilities of a hot/cryo-stage, controlled gas environment AFM.

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