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

Ferromagnetism01:31

Ferromagnetism

Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
Colors and Magnetism03:02

Colors and Magnetism

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 eye.
Valence Bond Theory02:42

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...
Paramagnetism01:30

Paramagnetism

Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis,  the precessing magnetic moments are randomly oriented around the z-axis. This...
Diamagnetism01:26

Diamagnetism

Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.

You might also read

Related Articles

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

Sort by
Same author

Gate-Tunable Floquet Weyl Photon Emission from Topological Dirac Semimetal Cd<sub>3</sub>As<sub>2</sub>.

Advanced materials (Deerfield Beach, Fla.)·2026
Same author

Room-Temperature Intrinsic Nonlinear Planar Hall Effect in TaIrTe_{4}.

Physical review letters·2026
Same author

Subterahertz Spin Relaxation Dynamics of Boron-Vacancy Centers in Hexagonal Boron Nitride.

Nano letters·2026
Same author

Acoustoelectric control of optoelectronic anisotropy for reconfigurable polarimetry.

Science advances·2026
Same author

Spintronic Bayesian Hardware Driven by Stochastic Magnetic Domain Wall Dynamics.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)·2026
Same author

Stack of Correlated Insulating States in Bilayer Graphene Kagome Superlattice.

Advanced materials (Deerfield Beach, Fla.)·2026

Related Experiment Video

Updated: Jun 10, 2026

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
15:58

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing

Published on: December 3, 2013

Voltage-controlled ferromagnetic order in MnGe quantum dots.

Faxian Xiu1, Igor V Ovchinnikov, Pramey Upadhyaya

  • 1Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, CA 90095-1594, USA. xiu@ee.ucla.edu

Nanotechnology
|August 21, 2010
PubMed
Summary

Room temperature ferromagnetism in dilute magnetic semiconductors is key for low-power spintronics. Researchers achieved voltage control of ferromagnetism in MnGe quantum dots, raising the Curie temperature for practical applications.

More Related Videos

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
07:42

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains

Published on: July 20, 2022

Fabrication of Magnetic Platforms for Micron-Scale Organization of Interconnected Neurons
09:54

Fabrication of Magnetic Platforms for Micron-Scale Organization of Interconnected Neurons

Published on: July 14, 2021

Related Experiment Videos

Last Updated: Jun 10, 2026

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
15:58

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing

Published on: December 3, 2013

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
07:42

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains

Published on: July 20, 2022

Fabrication of Magnetic Platforms for Micron-Scale Organization of Interconnected Neurons
09:54

Fabrication of Magnetic Platforms for Micron-Scale Organization of Interconnected Neurons

Published on: July 14, 2021

Area of Science:

  • Condensed Matter Physics
  • Materials Science
  • Nanotechnology

Background:

  • Dilute magnetic semiconductors (DMS) are promising for spintronics.
  • Controlling ferromagnetism at room temperature is crucial for next-generation devices.
  • Voltage control offers a low-power pathway for manipulating magnetic properties.

Purpose of the Study:

  • To explore voltage-controlled ferromagnetic ordering in DMS.
  • To investigate MnGe quantum dots as a material for spintronics.
  • To demonstrate the feasibility of raising the Curie temperature above room temperature.

Main Methods:

  • Experimental synthesis of MnGe quantum dots.
  • Application of voltage to manipulate ferromagnetic properties.
  • Measurement of Curie temperature and magnetic ordering.

Main Results:

  • Demonstrated voltage control of ferromagnetism in MnGe quantum dots.
  • Successfully pushed the Curie temperature above room temperature.
  • Confirmed the potential of DMS for spintronic applications.

Conclusions:

  • Voltage-controlled ferromagnetism in DMS is a viable phenomenon for spintronics.
  • MnGe quantum dots show promise for technological applications requiring room-temperature ferromagnetism.
  • Further research into DMS can lead to advanced low-power nanodevices.