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).

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.

Intrinsic Point Defects on a TiO2(110) Surface and Their Reaction with Oxygen: A Scanning Tunneling Microscopy Study

1997 ◽  
Vol 474 ◽  
Author(s):  
Markus Kuhn ◽  
J. F. Anderson ◽  
Jeremy Lehman ◽  
Talib Mahmoud ◽  
Ulrike Diebold
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Molecular Oxygen ◽  
Point Defects ◽  
Healing Process ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Defect Sites

ABSTRACTThe interaction of molecular oxygen, at room temperature, with a reduced TiO2(110) surface has been studied in situ by scanning tunneling microscopy (STM). Oxygen vacancies (point defects) were created on a clean TiO2(110) surface by annealing in ultra-high vacuum and successfully imaged on the atomic scale. These point defect sites were stable under ultrahigh vacuum conditions. During exposure to molecular oxygen, new point defects appear at different locations on the surface although their overall number is reduced. A mechanism for this dynamic healing process is proposed.

Structural Studies of Submonolayers of Carbon Atoms on Graphite

1992 ◽  
Vol 270 ◽  
Author(s):  
M. Ge ◽  
K. Sattler ◽  
J. Xhie ◽  
N. Venkateswaran
Keyword(s):  
Pyrolytic Graphite ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Carbon Particles ◽  
Linear Chains ◽  
High Vacuum Condition ◽  
Ultra High Vacuum Condition ◽  
Atomically Flat

ABSTRACTSubmonolayer coverages of carbon adsorbed on highly-oriented pyrolytic graphite were examined by scanning tunneling microscopy under ultra-high vacuum condition. Linear carbon wires were found on atomically flat graphite surfaces. The wires had different thicknesses, from single atomic width to about lnm. The long wires extended to over several hundred nanometers. Two directions, graphite β-β direction and 30° rotated, were preferred for the long wire orientation. Parallel wire alignment, with several nanometers of inter-wire spacings were observed. Carbon particles, from 0.7 to 2 nm in diameter were found to be attached to the carbon wires. Particles from different wires formed parallel linear chains about perpendicular to the wire direction.

Scanning Tunneling Microscopy Perspective of Structures on Reduced SrTiO3 (001) Surfaces

1992 ◽  
Vol 295 ◽  
Author(s):  
Yong Liang ◽  
Dawn A. Bonnell
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Structural Information ◽  
High Vacuum ◽  
Experimental Results ◽  
Ultra High Vacuum ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Sublimation Rates ◽  
Reduced Surface

AbstractScanning tunneling microscopy has been used in ultra high vacuum to provide atomic scale structural information on reduced SrTiO3(001) surfaces. Our tunneling images exhibit row-like features with 12 Å and 20 Å periodicities on the reduced surface. A local 2×1 reconstruction was also revealed on some regions of the surface. The experimental results are discussed in terms of the different sublimation rates of surface constituents and formation of lamella structures of Srn+lTinO3n+l.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document