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

2.4K
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...
2.4K
Magnetic Susceptibility and Permeability01:31

Magnetic Susceptibility and Permeability

1.2K
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...
1.2K
Diamagnetism01:26

Diamagnetism

2.4K
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....
2.4K
Magnetic Field due to Moving Charges01:23

Magnetic Field due to Moving Charges

8.8K
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
8.8K
Potential Due to a Magnetized Object01:24

Potential Due to a Magnetized Object

313
Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
313
Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

676
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.
676

You might also read

Related Articles

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

Sort by
Same author

Role of spin-orbit coupling in spin-to-lattice energy conversion in ferrite nanoparticles.

Scientific reports·2025
Same author

Microwave Negative Refractive Index Enabled by Anti-Parity-Time Symmetry in a Coupled Photon-Magnon Hybrid System.

Physical review letters·2025
Same author

Reconfigurable control of coherence, dissipation, and nonreciprocity in cavity magnonics.

Scientific reports·2025
Same author

Magnetic-field controlled on-off switchable non-reciprocal negative refractive index in non-Hermitian photon-magnon hybrid systems.

Nature communications·2024
Same author

Anomalous coherent and dissipative coupling in dual photon-magnon hybrid resonators.

Scientific reports·2024
Same author

Magnetically Actuated Trigger Transient Soft Actuators Comprising On-Demand Photo-Initiated and Thermo-Degradable Polypropylene Carbonate-Photo-Acid Generator.

ACS applied materials & interfaces·2024

Related Experiment Video

Updated: Jul 16, 2025

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

2.8K

Magnetization reversals in core-shell sphere clusters: finite-element micromagnetic simulation and machine learning

Hyeon-Kyu Park1, Sang-Koog Kim2

  • 1National Creative Research Initiative Center for Spin Dynamics and Spin-Wave Devices, Nanospinics Laboratory, Research Institute of Advanced Materials, Department of Materials Science and Engineering, Seoul National University, Seoul, 151-744, South Korea.

Scientific Reports
|September 14, 2023
PubMed
Summary

Engineered permanent magnets with inhomogeneous phases offer cost-effective alternatives. Machine learning analysis revealed stray fields are key to coercivity in these advanced magnetic materials.

More Related Videos

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
10:45

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition

Published on: February 5, 2022

4.3K
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

8.6K

Related Experiment Videos

Last Updated: Jul 16, 2025

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

2.8K
Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
10:45

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition

Published on: February 5, 2022

4.3K
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

8.6K

Area of Science:

  • Materials Science
  • Condensed Matter Physics
  • Computational Materials Science

Background:

  • Permanent magnets are crucial for various technologies.
  • Neodymium-Iron-Boron (Nd2Fe14B) magnets are high-performance but costly.
  • Inhomogeneous magnetic phases are explored as cost-effective alternatives.

Purpose of the Study:

  • To investigate Ce-substituted inhomogeneous Nd2-δCeδFe14B phases using a core-shell sphere cluster model.
  • To compare inhomogeneous phases with homogeneous magnetic phases.
  • To elucidate magnetization reversal mechanisms and identify key parameters influencing coercivity.

Main Methods:

  • Finite-element micromagnetic simulation.
  • Machine learning regression models.
  • Kernel SHapley Additive eXplanation (SHAP) technique.
  • Very fast simulated annealing algorithm for hyperparameter optimization.
  • Analytical modeling based on eigenvalue problems.

Main Results:

  • Grain-by-grain analysis of demagnetization curves revealed nucleation and coercive fields for individual spheres.
  • Nd-rich spheres showed broader distributions of nucleation and coercive fields than Nd-lean spheres.
  • Machine learning and SHAP analysis identified stray fields as crucial for coercivity.
  • Analytical models confirmed machine learning inferences.

Conclusions:

  • The study provides a grain-by-grain interpretation of magnetization reversal in inhomogeneous magnets.
  • Optimal design of granular hard magnets can be guided by adjusting microstructures and elemental compositions.
  • This research facilitates the development of high-performance, cost-effective permanent magnets using Nd2Fe14B and other rare earth elements.