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

Paramagnetism01:30

Paramagnetism

2.9K
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...
2.9K
Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

1.0K
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.
1.0K
Atomic Nuclei: Nuclear Spin State Population Distribution01:14

Atomic Nuclei: Nuclear Spin State Population Distribution

2.2K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
2.2K
Diamagnetism01:26

Diamagnetism

2.8K
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....
2.8K
Ferromagnetism01:31

Ferromagnetism

2.8K
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...
2.8K
Magnetic Susceptibility and Permeability01:31

Magnetic Susceptibility and Permeability

2.0K
In linear magnetic materials, like paramagnets and diamagnets, magnetization is proportional to the magnetic field intensity. The constant of proportionality, a dimensionless number, is called magnetic susceptibility. The value of the susceptibility depends on the type of material.
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
2.0K

You might also read

Related Articles

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

Sort by
Same author

Delay modulation with a glass chopper in pump-probe experiments.

The Review of scientific instruments·2019
See all related articles

Related Experiment Video

Updated: Dec 7, 2025

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene
08:25

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene

Published on: July 3, 2015

11.9K

Magnetic entropy dynamics in ultrafast demagnetization.

S Goharshenasanesfahani1, S Smadici1

  • 1Department of Physics and Astronomy, University of Louisville, KY 40292, United States of America.

Journal of Physics. Condensed Matter : an Institute of Physics Journal
|September 28, 2020
PubMed
Summary

Ultrafast demagnetization involves two distinct spin relaxation processes. Measurements reveal identical initial responses but differing relaxation times for magnetic properties.

Keywords:
magnetismmagneto-opticsultrafast

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

3.1K
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
08:55

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

8.8K

Related Experiment Videos

Last Updated: Dec 7, 2025

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene
08:25

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene

Published on: July 3, 2015

11.9K
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

3.1K
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
08:55

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

8.8K

Area of Science:

  • Condensed matter physics
  • Ultrafast magnetism

Background:

  • Ultrafast demagnetization is a key phenomenon in magnetism.
  • Understanding spin relaxation dynamics is crucial for magnetic applications.

Purpose of the Study:

  • To investigate the dynamics of magnetization and magnetic entropy during ultrafast demagnetization.
  • To elucidate the underlying spin relaxation processes.

Main Methods:

  • Utilized a double polarization and temperature modulation configuration.
  • Measured magnetization and magnetic entropy dynamics at ultrafast timescales.
  • Analyzed magnetic properties derived from measurements at opposite fields.

Main Results:

  • Identified two distinct magnetic properties with identical onsets at small time delays.
  • Observed different relaxation behaviors for these properties at larger time delays.
  • Demonstrated that spin relaxation is not a single-exponential process.

Conclusions:

  • Spin relaxation in ultrafast demagnetization comprises at least two distinct processes.
  • The differing relaxation dynamics provide insights into the fundamental mechanisms of demagnetization.