Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Valence Bond Theory

Valence Bond Theory

Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...

Valence Bond Theory

Valence Bond Theory

Overview of Valence Bond Theory

Spin–Spin Coupling: One-Bond Coupling

Spin–Spin Coupling: One-Bond Coupling

Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

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...

Atomic Nuclei: Nuclear Spin State Overview

Atomic Nuclei: Nuclear Spin State Overview

NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Evidence of Chiral Fermion Edge Modes through Geometric Engineering of Thermal Hall Effect in α-RuCl_{3}.

Physical review letters·2026

Same author

Anisotropic Ferromagnetism in CrAu<sub>3</sub>Sb<sub>6</sub>.

Chemistry of materials : a publication of the American Chemical Society·2026

Same author

A Non-Covalent [4Fe-4S]/[2Fe] Interface in HydF Guides [FeFe]-Hydrogenase Maturation.

Angewandte Chemie (International ed. in English)·2026

Same author

Dynamics of Spinal Fluid Immune Cell Alterations Following Cladribine Tablet Treatment in Multiple Sclerosis.

Neurology(R) neuroimmunology & neuroinflammation·2026

Same author

Intrinsic topological Weyl phase transition induced by a magnetostructural transformation in a kagome magnet.

Nature communications·2026

Same author

Tumor Microenvironment and Immune Response Against Wilms Tumor: Evasion Mechanisms and Implications for Immunotherapeutic Approaches.

Cancers·2026

Search research articles

Related Experiment Video

Updated: May 18, 2026

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe₁₊_YTe Using a Spin-polarized Scanning Tunneling Microscope

Published on: March 24, 2019

Spin reorientation in TlFe1.6Se2 with complete vacancy ordering.

Andrew F May¹, Michael A McGuire, Huibo Cao

¹Materials Science and Technology Division, Oak Ridge National Laboratory, Tennessee 37831, USA.

Physical Review Letters

|September 26, 2012

Summary

Vacancy ordering in TlFe(1.6)Se(2) influences magnetism, revealing a true ground state with in-plane magnetic moments. This contrasts with disordered regions, suggesting coupled effects in superconducting analogues.

More Related Videos

Theoretical Calculation and Experimental Verification for Dislocation Reduction in Germanium Epitaxial Layers with Semicylindrical Voids on Silicon

Theoretical Calculation and Experimental Verification for Dislocation Reduction in Germanium Epitaxial Layers with Semicylindrical Voids on Silicon

Published on: July 17, 2020

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Published on: June 28, 2018

Related Experiment Videos

Last Updated: May 18, 2026

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe₁₊_YTe Using a Spin-polarized Scanning Tunneling Microscope

Published on: March 24, 2019

Theoretical Calculation and Experimental Verification for Dislocation Reduction in Germanium Epitaxial Layers with Semicylindrical Voids on Silicon

Theoretical Calculation and Experimental Verification for Dislocation Reduction in Germanium Epitaxial Layers with Semicylindrical Voids on Silicon

Published on: July 17, 2020

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

Published on: June 28, 2018

Area of Science:

Condensed Matter Physics
Materials Science
Solid State Chemistry

Background:

Investigating the interplay between crystal structure and magnetic properties is crucial for understanding novel materials.
TlFe(1.6)Se(2) exhibits complex magnetic behavior influenced by vacancy ordering.

Purpose of the Study:

To elucidate the relationship between vacancy ordering and the magnetic ground state in TlFe(1.6)Se(2).
To clarify the magnetic moment orientation in homogeneous versus partially disordered crystals.

Main Methods:

Single crystal neutron diffraction
Nuclear forward scattering
Transmission electron microscopy

Main Results:

Homogeneous TlFe(1.6)Se(2) crystals display Fe magnetic moments aligned in the ab plane below 100 K.
Partially disordered crystals show competing magnetic moment orientations (c-axis vs. ab plane).
Properties of disordered TlFe(1.6)Se(2) are not solely from ordered or disordered regions.

Conclusions:

The true ground state of TlFe(1.6)Se(2) is characterized by in-plane magnetic ordering.
Phase separation in intercalated iron selenides may involve coupling between ordered and disordered regions.
This coupling could be significant for understanding superconducting analogues.