Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Valence Bond Theory02:42

Valence Bond Theory

11.9K
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...
11.9K
The Hall Effect01:30

The Hall Effect

5.5K
Edwin H. Hall, in the year 1879, devised an experiment that could be used to identify the polarity of the predominant charge carriers in a conducting material. From a historical perspective, this experiment was the first to demonstrate that the charge carriers in most metals are negative.
5.5K
Crystal Field Theory - Octahedral Complexes02:58

Crystal Field Theory - Octahedral Complexes

32.2K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
32.2K
Colors and Magnetism03:02

Colors and Magnetism

14.9K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
14.9K
Crystal Field Theory - Tetrahedral and Square Planar Complexes02:46

Crystal Field Theory - Tetrahedral and Square Planar Complexes

50.1K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
50.1K
Theory of Metallic Conduction01:17

Theory of Metallic Conduction

2.0K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
2.0K

You might also read

Related Articles

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

Sort by
Same author

Generative Model for Constructing Reaction Path from Initial to Final States.

Journal of chemical theory and computation·2025
Same author

Molecular Characterization and Risk Factors of Carbapenem-Resistant Hypervirulent <i>Klebsiella pneumoniae</i> Isolated from Chinese Tertiary Hospital.

Infection and drug resistance·2025
Same author

Resolving electrochemically triggered topological defect dynamics and structural degradation in layered oxides.

Proceedings of the National Academy of Sciences of the United States of America·2025
Same author

Characterization of MADS-Box Gene Family in <i>Isatis indigotica</i> and Functional Study of <i>IiAP1</i> in Regulating Floral Transition and Formation.

Plants (Basel, Switzerland)·2025
Same author

Mismatch prime editing gRNA increased efficiency and reduced indels.

Nature communications·2025
Same author

Smoking-attributable peptic ulcer disease mortality worldwide: trends from 1990 to 2021 and projections to 2046 based on the global burden of disease study.

Frontiers in public health·2025

Related Experiment Video

Updated: Apr 19, 2026

Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
08:12

Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures

Published on: December 5, 2015

12.9K

Solid state theory. Quantum spin Hall effect in two-dimensional transition metal dichalcogenides.

Xiaofeng Qian1, Junwei Liu2, Liang Fu3

  • 1Department of Nuclear Science and Engineering and Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

Science (New York, N.Y.)
|December 16, 2014
PubMed
Summary

We discovered large-gap quantum spin Hall (QSH) insulators in 2D transition metal dichalcogenides. These materials offer tunable band gaps and potential for novel topological transistors, overcoming limitations of current QSH materials.

More Related Videos

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating
10:36

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating

Published on: April 12, 2018

12.1K
Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication
08:50

Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication

Published on: November 28, 2017

9.7K

Related Experiment Videos

Last Updated: Apr 19, 2026

Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
08:12

Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures

Published on: December 5, 2015

12.9K
Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating
10:36

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating

Published on: April 12, 2018

12.1K
Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication
08:50

Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication

Published on: November 28, 2017

9.7K

Area of Science:

  • Condensed Matter Physics
  • Materials Science
  • Quantum Chemistry

Background:

  • Quantum spin Hall (QSH) effect materials possess topologically protected edge states.
  • Limited applications due to small band gaps in existing QSH insulators.

Purpose of the Study:

  • Predict novel large-gap QSH insulators.
  • Explore tunable band gaps and topological phase transitions in 2D materials.
  • Propose a new type of topological field effect transistor.

Main Methods:

  • First-principles calculations.
  • Investigating two-dimensional transition metal dichalcogenides (1T'-MX2).
  • Analyzing band inversion and spin-orbit coupling effects.

Main Results:

  • Predicted a class of large-gap QSH insulators in 1T'-MX2 (W/Mo, Te/Se/S).
  • Identified intrinsic band inversion and tunable band gaps via electric field and strain.
  • Proposed a topological field effect transistor with electric-field-induced switching.

Conclusions:

  • 1T'-MX2 materials are promising candidates for large-gap QSH insulators.
  • Tunable band gaps and topological phase transitions enable advanced electronic devices.
  • The proposed topological transistor offers an alternative to carrier depletion switching.