Direct measurement of interatomic force gradients using an ultra-low-amplitude atomic force microscope

Download

index.pdf

Date

2001-05-08

Author

HOFFMANN, P M
Oral, Ahmet
GRİMBLE, R A
ÖZER, HAKAN ÖZGÜR
JEFFERY, S
PETHİCA, J B

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

57
views

0
downloads

Interatomic force gradients between a W tip and a 7x7 reconstructed Si(lll) surface were measured using an off-resonance, ultra-low-amplitude atomic force microscope (AFM) technique. The amplitudes used were less than 1 Angstrom (peak-to-peak), which allowed direct measurement of the interaction force gradients as a function of separation. The force gradient curves are shown to consist of an attractive van der Waals part and short-range attractive and repulsive interactions. The van der Waals background can be subtracted, leaving a short-range interaction with an energy parameter of 1.9-3.4 eV and an interaction length-scale of 0.54-1.26 Angstrom, characteristic of a single atomic bond. This correlates well with our observation of single-atom resolved force gradient images. In general, the interaction is reversible up to the zero intercept of the force gradient (inflection point of the energy). Beyond this point hysteresis tends to be observed and the onset of inelastic deformation can be clearly discerned. An analysis of the atomic scale contact gives reasonable values for the interfacial energy, yield strength, and the energy per atom needed to initiate plastic deformation.

Subject Keywords

Atomic force microscopy, Interatomic potentials, Nanomechanics, Contact mechanics, Atomic scale imaging

URI

https://hdl.handle.net/11511/40217

Journal

PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES

DOI

https://doi.org/10.1098/rspa.2000.0713

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

Simultaneous non-contact atomic force microscopy (nc-AFM)/STM imaging and force spectroscopy of Si(1 0 0)(2 × 1) with small oscillation amplitudes Özer, H.Özgür; Atabak, Mehrdad; Ellialtǧlu, Recai M.; Oral, Ahmet (2002-03-28) Si(1 0 0)(2 x 1) surface is imaged using a new non-contact atomic force microscopy (nc-AFM)/STM with sub-Angstrom oscillation amplitudes using stiff tungsten levers. Simultaneous force gradient and STM images of individual dimers and atomic scale defects are obtained. We measured force-distance (f-d) curves with different tips. Some of the tips show long force interactions, whereas some others resolve short-range interatomic force interactions. We observed that the tips showing short-range force interaction...
Quantitative atom-resolved force gradient imaging using noncontact atomic force microscopy Oral, Ahmet; ÖZER, HAKAN ÖZGÜR; HOFFMANN, PM; PETHICA, JB (2001-09-17) Quantitative force gradient images are obtained using a sub-angstrom amplitude, off-resonance lever oscillation method during scanning tunneling microscopy imaging. We report the direct observation of short-range bonds, and the measured short-range force interaction agrees well in magnitude and length scale with theoretical predictions for single bonds. Atomic resolution is shown to be associated with the presence of a prominent short-range contribution to the total force interaction. It is shown that the b...
Direct numerical simulation of liquid flow in a horizontal microchannel Kükrer, Cenk Evren; Tarı, İlker; Department of Mechanical Engineering (2005) Numerical simulations of liquid flow in a micro-channel between two horizontal plates are performed. The channel is infinite in streamwise and spanwise directions and its height is taken as m, which falls within the dimension ranges of microchannels. The Navier-Stokes equations with the addition of Brinkman number (Br) to the energy equation are used as the governing equations and spectral methods based approach is applied to obtain the required accuracy to handle liquid flow in the microchannel. It is know...
Direct Numerical Simulation of Liquid Flow in a Horizontal Microchannel Tarı, İlker (2005-07-21) Numerical Simulations of liquid flow in a micro-channel between two horizontal plates are performed. The channel is infinite in streamwise and spanwise directions and its height is taken as 3.1 x 10(-4) m which falls within the dimension ranges of micro-channels. The Navier-Stokes equations with the addition of Brinkman number (Br) to the energy equation are used as the governing equations and a spectral methods based approach is applied to obtain the required accuracy to handle liquid flow in the micro-cha...
Numerical investigation of unsteady natural convection from a heated cylinder in a square enclosure Bozkaya, Canan (null; 2015-07-06) A numerical study of two dimensional, unsteady, incompressible natural convection flow and heat transfer is performed in a square enclosure involving a heated circular cylinder. The natural convection is driven by a temperature difference between the cold outer square and hot inner circular cylinders. The temperature of the inner cylinder varies sinusoidally with time about a fixed mean temperature while the outer enclosure is kept at a lower constant temperature. The problem under consideration, which is g...

Citation Formats

P. M. HOFFMANN, A. Oral, R. A. GRİMBLE, H. Ö. ÖZER, S. JEFFERY, and J. B. PETHİCA, “Direct measurement of interatomic force gradients using an ultra-low-amplitude atomic force microscope,” PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, pp. 1161–1174, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40217.