Related Experiment Video
Updated: Jun 20, 2025
07:03
Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals
Published on: August 15, 2018
8.7K
Macroscopic dynamics of ferromagnetic smectic-A.
Harald Pleiner1, Helmut R Brand1,2
1<a href="https://ror.org/00sb7hc59">Max Planck Institute for Polymer Research</a>, 55021 Mainz, Germany.
Physical Review. E
|July 18, 2024
Summary
We developed dynamic equations for ferromagnetic smectic-A liquid crystals, revealing cross-coupling effects between magnetization and material properties. These findings predict observable changes in sound velocities and material responses.
Area of Science:
- Condensed Matter Physics
- Soft Matter Physics
- Liquid Crystals
Background:
- Ferromagnetic liquid crystals combine magnetic and liquid crystal properties.
- Smectic-A liquid crystals exhibit layered structures with specific order parameters.
Purpose of the Study:
- To derive macroscopic dynamic equations for ferromagnetic smectic-A liquid crystals.
- To investigate cross-coupling phenomena between magnetization and hydrodynamic variables.
Main Methods:
- Macroscopic dynamic equations derivation.
- Analysis of reversible and dissipative cross-coupling terms.
- Theoretical investigation of sound propagation and static properties.
Main Results:
- Identified cross-coupling between magnetization and layer displacement/compression.
- Predicted anisotropic sound velocities (first sound) and modified second sound velocities.
- Observed temperature gradient-induced magnetization gradients via layer compression.
Conclusions:
- The study provides a theoretical framework for ferromagnetic smectic-A liquid crystals.
- Cross-coupling effects offer potential experimental avenues for characterization.
- Magnetization significantly influences the dynamic and static properties of these materials.
More Related Videos
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
8.5K
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.1K
Related Concept Videos
01:31Ferromagnetism
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
01:26Diamagnetism
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....
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
01:30Paramagnetism
2.5K
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...
2.5K
01:31Magnetic Susceptibility and Permeability
1.0K
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...
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...
1.0K
01:28Magnetostatic Boundary Conditions
905
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
905
01:23Atomic Nuclei: Nuclear Relaxation Processes
644
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.
644