scholarly journals Quantitative determination of atomic buckling of silicene by atomic force microscopy

2019 ◽  
Vol 117 (1) ◽  
pp. 228-237 ◽  
Author(s):  
Rémy Pawlak ◽  
Carl Drechsel ◽  
Philipp D’Astolfo ◽  
Marcin Kisiel ◽  
Ernst Meyer ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Electronic Properties ◽  
Density Functional ◽  
Local Symmetry ◽  
Quantum Spin ◽  
Atomic Scale ◽  
Extended Defects ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structural And Electronic Properties

The atomic buckling in 2D “Xenes” (such as silicene) fosters a plethora of exotic electronic properties such as a quantum spin Hall effect and could be engineered by external strain. Quantifying the buckling magnitude with subangstrom precision is, however, challenging, since epitaxially grown 2D layers exhibit complex restructurings coexisting on the surface. Here, we characterize using low-temperature (5 K) atomic force microscopy (AFM) with CO-terminated tips assisted by density functional theory (DFT) the structure and local symmetry of each prototypical silicene phase on Ag(111) as well as extended defects. Using force spectroscopy, we directly quantify the atomic buckling of these phases within 0.1-Å precision, obtaining corrugations in the 0.8- to 1.1-Å range. The derived band structures further confirm the absence of Dirac cones in any of the silicene phases due to the strong Ag-Si hybridization. Our method paves the way for future atomic-scale analysis of the interplay between structural and electronic properties in other emerging 2D Xenes.

scholarly journals Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

2014 ◽  
Vol 5 ◽  
pp. 386-393 ◽  
Author(s):  
Adam Sweetman ◽  
Andrew Stannard
Keyword(s):  
Atomic Force Microscopy ◽  
Long Range ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Extrapolation Method ◽  
Atomic Scale ◽  
Site Specific ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fitting Method

In principle, non-contact atomic force microscopy (NC-AFM) now readily allows for the measurement of forces with sub-nanonewton precision on the atomic scale. In practice, however, the extraction of the often desired ‘short-range’ force from the experimental observable (frequency shift) is often far from trivial. In most cases there is a significant contribution to the total tip–sample force due to non-site-specific van der Waals and electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a commonly used extrapolation method modelling the long-range forces using a simple power law. By examining the behaviour of the fitting method in the case of two radically different interaction potentials we show that significant uncertainties in the final extracted forces may result from use of the extrapolation method.

Atomic Force Microscopy of Atomic-Scale Ledges and Etch Pits Formed During Dissolution of Quartz

Science ◽  
1991 ◽  
Vol 251 (4999) ◽  
pp. 1343-1346 ◽  
Author(s):  
A. J. GRATZ ◽  
S. MANNE ◽  
P. K. HANSMA
Keyword(s):  
Atomic Force Microscopy ◽  
Atomic Scale ◽  
Etch Pits ◽  
Force Microscopy ◽  
Atomic Force

Nanoindentation studies of sublimed fullerene films using atomic force microscopy

1993 ◽  
Vol 8 (12) ◽  
pp. 3019-3022 ◽  
Author(s):  
Juai Ruan ◽  
Bharat Bhushan
Keyword(s):  
Atomic Force Microscopy ◽  
Transfer Film ◽  
Atomic Scale ◽  
Diamond Surface ◽  
Low Friction ◽  
Force Microscopy ◽  
Diamond Sample ◽  
Atomic Force ◽  
Molecular Scale ◽  
Deposited Films

Nanoindentation studies of sublimed fullerene films have been conducted using an atomic force microscope (AFM). Transfer of fullerene molecules from the as-deposited films to the AFM tip was observed during the indentation of AFM tip into some of the samples, whereas such a transfer was not observed for ion-bombarded films. The fullerene molecules transferred to the AFM tip were subsequently transported to a diamond surface when the diamond sample was scanned with the contaminated tip. This demonstrates the capability of material manipulation on a molecular scale using AFM. Atomic-scale friction of the fullerene films was measured to be low. Ability of fullerene films to form transfer film on the mating AFM tip surface may be partly responsible for low friction.

Direct observations of mineral fluid reactions using atomic force microscopy: the specific example of calcite

2012 ◽  
Vol 76 (1) ◽  
pp. 227-253 ◽  
Author(s):  
E. Ruiz -Agudo ◽  
C. V. Putnis
Keyword(s):  
Atomic Force Microscopy ◽  
Atomic Scale ◽  
Physical Parameters ◽  
Extensive Literature ◽  
Mineral Surfaces ◽  
Kinetic Measurements ◽  
Force Microscopy ◽  
Crystal Dissolution ◽  
Direct Observations ◽  
Atomic Force

AbstractAtomic force microscopy (AFM) enables in situ observations of mineral fluid reactions to be made at a nanoscale. During the past 20 years, the direct observation of mineral surfaces at molecular resolution during dissolution and growth has made significant contributions toward improvements in our understanding of the dynamics of mineral fluid reactions at the atomic scale. Observations and kinetic measurements of dissolution and growth from AFM experiments give valuable evidence for crystal dissolution and growth mechanisms, either confirming existing models or revealing their limitations. Modifications to theories can be made in the light of experimental evidence generated by AFM. Significant changes in the kinetics and mechanisms of crystallization and dissolution processes occur when the chemical and physical parameters of solutions, including the presence of impurity molecules or background electrolytes, are altered. Calcite has received considerable attention in AFM studies due to its central role in geochemical and biomineralization processes. This review summarizes the extensive literature on the dissolution and growth of calcite that has been generated by AFM studies, including the influence of fluid characteristics such as supersaturation, solution stoichiometry, pH, temperature and the presence of impurities.

scholarly journals Atomic Resolution with the Atomic Force Microscope

1995 ◽  
Vol 3 (4) ◽  
pp. 6-7
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Atomic Force Microscopy ◽  
Scanning Tunneling Microscopy ◽  
Atomic Force Microscope ◽  
Recent Article ◽  
Atomic Scale ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force

For biologic studies, atomic force microscopy (AFM) has been prevailing over scanning tunneling microscopy (STM) because it has the capability of imaging non-conducting biologic specimens. However, STM generally gives better resolution than AFM, and we're talking about resolution on the atomic scale. In a recent article, Franz Giessibl (Atomic resolution of the silicon (111)- (7X7) surface by atomic force microscopy, Science 267:68-71, 1995) has demonstrated that atoms can be imaged by AFM.

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