Nanotribology of Diamond Films Studied by Atomic Force Microscopy

1990 ◽  
Vol 188 ◽  
Author(s):  
Gabi Neubauer ◽  
Sidney R. Cohen ◽  
Gary M. Mcclelland ◽  
Hajime Seki
Keyword(s):  
High Vacuum ◽  
Diamond Films ◽  
Ultra High Vacuum ◽  
Nanometer Scale ◽  
Kinetic Friction ◽  
Experimental Conditions ◽  
Stick Slip ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Difference

ABSTRACTAn atomic force microscope, operated in ultra-high vacuum has been employed to study the tribological properties of diamond films under small loads (< 10−6 N) on a nanometer scale. The incidence of intermittent motion, “stick-slip”, while sliding a diamond tip across the diamond film, is detected under certain experimental conditions and is discussed with respect to the difference between static and kinetic friction, sample topography and a varying sample condition.

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.

scholarly journals Generic nature of long-range repulsion mechanism on a bulk insulator?

2017 ◽  
Vol 204 ◽  
pp. 419-428 ◽  
Author(s):  
J. L. Neff ◽  
A. Richter ◽  
H. Söngen ◽  
C. Venturini ◽  
A. Gourdon ◽  
...  
Keyword(s):  
Long Range ◽  
Self Assembly ◽  
Room Temperature ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Experimental Conditions ◽  
Force Microscopy ◽  
Benzoic Acid Derivatives ◽  
Atomic Force ◽  
Kinetic Effects

Dynamic atomic force microscopy measurements are reported that provide evidence for the presence of long-range repulsion in molecular self-assembly on a bulk insulator surface. We present the structures formed from four different benzoic acid derivatives on the (10.4) cleavage plane of calcite kept in ultra-high vacuum. These molecules have in common that they self-assemble into molecular stripes when deposited onto the surface held at room temperature. For all molecules tested, a detailed analysis of the stripe-to-stripe distance distribution reveals a clear deviation from what would be expected for randomly placed, non-interacting stripes (i.e., geometric distribution). When excluding kinetic effects during growth, this result gives evidence for a long-range repulsion mechanism acting during the assembly of these stripes. The fact that this finding is robust against changes in the molecular structure indicates a generic nature of the observed mechanism, implying a ubiquitous origin such as electrostatic repulsion. Finally, we discuss parameters that might affect the unambiguous observation of this generic repulsion under specific experimental conditions.

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.

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.

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.

scholarly journals Effect of the tip state during qPlus noncontact atomic force microscopy of Si(100) at 5 K: Probing the probe

2012 ◽  
Vol 3 ◽  
pp. 25-32 ◽  
Author(s):  
Adam Sweetman ◽  
Sam Jarvis ◽  
Rosanna Danza ◽  
Philip Moriarty
Keyword(s):  
Atomic Force Microscopy ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Dissipated Energy ◽  
Tunnel Current ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range ◽  
Characteristic Imaging

Background: Noncontact atomic force microscopy (NC-AFM) now regularly produces atomic-resolution images on a wide range of surfaces, and has demonstrated the capability for atomic manipulation solely using chemical forces. Nonetheless, the role of the tip apex in both imaging and manipulation remains poorly understood and is an active area of research both experimentally and theoretically. Recent work employing specially functionalised tips has provided additional impetus to elucidating the role of the tip apex in the observed contrast. Results: We present an analysis of the influence of the tip apex during imaging of the Si(100) substrate in ultra-high vacuum (UHV) at 5 K using a qPlus sensor for noncontact atomic force microscopy (NC-AFM). Data demonstrating stable imaging with a range of tip apexes, each with a characteristic imaging signature, have been acquired. By imaging at close to zero applied bias we eliminate the influence of tunnel current on the force between tip and surface, and also the tunnel-current-induced excitation of silicon dimers, which is a key issue in scanning probe studies of Si(100). Conclusion: A wide range of novel imaging mechanisms are demonstrated on the Si(100) surface, which can only be explained by variations in the precise structural configuration at the apex of the tip. Such images provide a valuable resource for theoreticians working on the development of realistic tip structures for NC-AFM simulations. Force spectroscopy measurements show that the tip termination critically affects both the short-range force and dissipated energy.

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