Laser cleaning of exfoliated graphene

2012 ◽  
Vol 1455 ◽  
Author(s):  
Oliver Ochedowski ◽  
Benedict Kleine Bußmann ◽  
Marika Schleberger
Keyword(s):  
Local Heating ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ambient Conditions ◽  
Kelvin Probe ◽  
Structural Modifications ◽  
Force Microscopy ◽  
Exfoliated Graphene ◽  
Atomic Force ◽  
P Type

ABSTRACTWe have employed atomic force and Kelvin-Probe force microscopy to study graphene sheets exfoliated on TiO2 under the influence of local heating achieved by laser irradiation. Exfoliation and irradiation took place under ambient conditions, the measurements were performed in ultra high vacuum. We show that after irradiation times of 6 min, an increase of the surface potential is observed which indicates a decrease of p-type carrier concentration. We attribute this effect to the removal of adsorbates like water and oxygen. After irradiation times of 12 min our topography images reveal severe structural modifications of graphene. These resemble the nanocrystallite network which form on graphene/SiO2 but after much longer irradiation times. From our results we propose that short laser heating at moderate powers might offer a way to clean graphene without inducing unwanted structural modifications.

scholarly journals Elucidating the charge state of an Au nanocluster on the oxidized/reduced rutile TiO2 (110) surface using non-contact atomic force microscopy and Kelvin probe force microscopy

2020 ◽  
Vol 2 (6) ◽  
pp. 2371-2375 ◽  
Author(s):  
Yuuki Adachi ◽  
Huan Fei Wen ◽  
Quanzhen Zhang ◽  
Masato Miyazaki ◽  
Yasuhiro Sugawara ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Charge State ◽  
High Vacuum ◽  
Kelvin Probe Force Microscopy ◽  
Ultra High Vacuum ◽  
Kelvin Probe ◽  
Au Nanoclusters ◽  
Rutile Tio2 ◽  
Force Microscopy ◽  
Atomic Force

The charge state of Au nanoclusters on oxidized/reduced rutile TiO2 (110) surfaces were investigated by a combination of non-contact atomic force microscopy and Kelvin probe force microscopy at 78 K under ultra-high vacuum.

High-sensitivity quantitative Kelvin probe microscopy by noncontact ultra-high-vacuum atomic force microscopy

1999 ◽  
Vol 75 (2) ◽  
pp. 286-288 ◽  
Author(s):  
Ch. Sommerhalter ◽  
Th. W. Matthes ◽  
Th. Glatzel ◽  
A. Jäger-Waldau ◽  
M. Ch. Lux-Steiner
Keyword(s):  
Atomic Force Microscopy ◽  
High Vacuum ◽  
High Sensitivity ◽  
Ultra High Vacuum ◽  
Kelvin Probe ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Length-extension resonator as a force sensor for high-resolution frequency-modulation atomic force microscopy in air

2016 ◽  
Vol 7 ◽  
pp. 432-438 ◽  
Author(s):  
Hannes Beyer ◽  
Tino Wagner ◽  
Andreas Stemmer
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Frequency Modulation ◽  
High Vacuum ◽  
Force Sensor ◽  
Ultra High Vacuum ◽  
Dew Point ◽  
Ambient Conditions ◽  
Force Microscopy ◽  
Atomic Force

Frequency-modulation atomic force microscopy has turned into a well-established method to obtain atomic resolution on flat surfaces, but is often limited to ultra-high vacuum conditions and cryogenic temperatures. Measurements under ambient conditions are influenced by variations of the dew point and thin water layers present on practically every surface, complicating stable imaging with high resolution. We demonstrate high-resolution imaging in air using a length-extension resonator operating at small amplitudes. An additional slow feedback compensates for changes in the free resonance frequency, allowing stable imaging over a long period of time with changing environmental conditions.

Fundamental study of the interaction of Ti atoms with spruce surfaces

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 523-527 ◽  
Author(s):  
Lothar Klarhöfer ◽  
Florian Voigts ◽  
Dominik Schwendt ◽  
Burkhard Roos ◽  
Wolfgang Viöl ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Strong Interactions ◽  
Titanium Oxide Film ◽  
Fundamental Study ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Metal Atoms

Abstract Metastable induced electron spectroscopy (MIES), ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were applied to study the interaction of Ti metal atoms with spruce surfaces. Spruce surfaces were produced by planing splints from a spruce bar. Ti atoms were adsorbed from a metal evaporator under ultra-high vacuum conditions. The amount adsorbed corresponds to 10 monolayer equivalents. Strong interactions between the spruce surface and metals atoms occurred. Impinging Ti atoms were oxidized by the spruce surface. No Ti agglomeration or particle formation was observed. The surface was smoothed by the Ti applied and was completely covered by a titanium oxide film.

Development of a Self-Excited Oscillator for SI-Traceable Measurements in Atomic Force Microscopy

2008 ◽  
Author(s):  
Gregory W. Vogl ◽  
Jon R. Pratt
Keyword(s):  
Atomic Force Microscopy ◽  
International System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Force Microscopy ◽  
Atomic Force ◽  
Force Transducers ◽  
Analog Control ◽  
System Of Units ◽  
Excited Oscillator

A new self-excited micro-oscillator is proposed as a velocity reference that could aid the dissemination of nanonewton-level forces that are traceable to the International System of Units (SI). An analog control system is developed to keep the actuation side of the device oscillating sinusoidally with an amplitude that is fairly insensitive to the quality factor. Consequently, the device can be calibrated as a velocity reference in air and used in ultra-high vacuum with a velocity shift of less than one percent. Hence, the calibrated micro-oscillator could be used with electrostatic forces to calibrate cantilevers used for atomic force microscopy (AFM) as SI-traceable force transducers. Furthermore, the calibrated micro-oscillator could potentially be used as an AFM sensor to achieve atomic resolutions on par with those realized in frequency-modulation AFM (FM-AFM) with quartz tuning forks.

Atomic-Force Microscopy with piezoresistive cantilevers

1994 ◽  
Vol 52 ◽  
pp. 1064-1065
Author(s):  
M. Tortonese ◽  
F. J. Giessibl
Keyword(s):  
Atomic Force Microscopy ◽  
Electron Tunneling ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Cantilever Deflection ◽  
Force Microscopy ◽  
Large Samples ◽  
Atomic Force ◽  
High Lateral Resolution ◽  
Piezoresistive Cantilevers

The atomic force microscope (AFM) works by measuring the deflection of a cantilever as it is scanned over a sample. A sharp tip at the end of the cantilever is responsible for the high lateral resolution achieved with the AFM. There are several ways to measure the deflection of the cantilever. The technique used to measure the deflection of the cantilever most often dictates the mechanical complexity and stability of the instrument. Electron tunneling, interferometry and capacitive sensors have been used successfully. The most common way to measure the cantilever deflection is by means of an optical deflection detector.The piezoresistivc cantilever offers a new way to measure the deflection of the cantilever, with performances comparable to the performances of other deflection detectors, and with the advantage that the sensor is incorporated in the cantilever. This simplifies the design and operation of the microscope In particular, the piezoresistive cantilever facilitates the use and often improves the performances of an AFM when operated in ultra high vacuum (UHV), at low temperature, or when used to image large samples.

scholarly journals Surface Sensitivity Effects With Local Probe Scanning Auger-Scanning Electron Microscopy

1999 ◽  
Vol 589 ◽  
Author(s):  
D. T. L. Van Agterveld ◽  
G. Palasantzas ◽  
J.Th.M. De Hosson
Keyword(s):  
Electron Microscopy ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Precipitate Size ◽  
Nanometer Scale ◽  
Force Microscopy ◽  
Surface Sensitivity ◽  
Atomic Force ◽  
Microscopy Analysis

AbstractUltra-high-vacuum segregation studies on in-situ fractured Cu-Sb alloys were performed in terms of nanometer scale scanning Auger/Electron microscopy. S contamination leads to the formation of Cu2S precipitates which, upon removal due to fracture, expose pits with morphology that depends on the precipitate size and shape. Local variations of S and Sb distributions inside the pits were correlated to local surface orientations as Atomic Force Microscopy analysis revealed.

Linear measurements of nanomechanical phenomena using small-amplitude AFM

2004 ◽  
Vol 838 ◽  
Author(s):  
Peter M. Hoffmann ◽  
Shivprasad Patil ◽  
George Matei ◽  
Atay Tanulku ◽  
Ralph Grimble ◽  
...  
Keyword(s):  
High Vacuum ◽  
Data Interpretation ◽  
Ultra High Vacuum ◽  
Atomic Scale ◽  
Single Atom ◽  
Linear Measurements ◽  
Interaction Range ◽  
Force Microscopy ◽  
Atomic Force ◽  
Molecular Ordering

ABSTRACTDynamic Atomic Force Microscopy (AFM) is typically performed at amplitudes that are quite large compared to the measured interaction range. This complicates the data interpretation as measurements become highly non-linear. A new dynamic AFM technique in which ultra-small amplitudes are used (as low as 0.15 Angstrom) is able to linearize measurements of nanomechanical phenomena in ultra-high vacuum (UHV) and in liquids. Using this new technique we have measured single atom bonding, atomic-scale dissipation and molecular ordering in liquid layers, including water.

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