Related Experiment Video
Updated: May 2, 2026
06:53
Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
7.5K
Unique determination of "subatomic" contrast by imaging covalent backbonding
Adam Sweetman1, Philipp Rahe, Philip Moriarty
1The School of Physics and Astronomy, The University of Nottingham , Nottingham NG7 2RD, United Kingdom.
Nano Letters
|March 18, 2014
Summary
Researchers have uncovered the cause of subatomic resolution in dynamic force microscopy. This study identifies back bonding of a surface atom in the tip-sample junction as the source of subatomic contrast.
Area of Science:
- Surface science
- Atomic force microscopy
- Nanotechnology
Background:
- The origin of subatomic resolution in dynamic force microscopy (DFM) has been debated since its initial observation.
- Previous research proposed various physicochemical mechanisms for subatomic contrast.
Purpose of the Study:
- To definitively identify the cause of a specific instance of subatomic contrast observed in DFM.
- To elucidate the fundamental mechanisms behind high-resolution imaging in DFM.
Main Methods:
- Utilized advanced dynamic force microscopy techniques.
- Conducted detailed experimental analysis of the tip-sample junction.
- Applied theoretical modeling to interpret experimental observations.
Main Results:
- For the first time, the study assigns a specific instance of subatomic contrast to a distinct physical phenomenon.
- Identified the back bonding of a surface atom within the tip-sample junction as the source of subatomic contrast.
Conclusions:
- The findings resolve a long-standing controversy regarding subatomic resolution in DFM.
- Back bonding in the tip-sample junction is confirmed as a key mechanism for achieving subatomic contrast.
- This provides a clearer understanding of the capabilities and limitations of DFM for atomic-scale imaging.
Related Concept Videos
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
1.5K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.5K
01:04¹³C NMR: ¹H–¹³C Decoupling
1.7K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.7K
01:182D NMR: Overview of Heteronuclear Correlation Techniques
905
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
905
01:13¹H NMR: Complex Splitting
1.7K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.7K
02:40Chemical Bonds
16.3K
Atoms participate in a chemical bond formation to acquire a completed valence-shell electron configuration similar to that of the noble gas nearest to it in atomic number. Ionic, covalent, and metallic bonds are some of the important types of chemical bonds. Bond energy and bond length determine the strength of a chemical bond.
Types of Chemical Bonds
An ionic bond is formed due to electrostatic attraction between cations and anions. Often, the ions are formed by the transfer of electrons...
16.3K
01:12Double Resonance Techniques: Overview
870
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
870