Liquid crystals: dielectric torque and electric torque

  • #1
shpongle
Dear Members,

I was reading a tutorial on ferroelectricity of liquid crystals, underneath is the excrept:

"For ferroelectric materials, in addition to the dielectric torque, the electric torque will have a term due to the linear coupling between the spontaneous polarization"

Could someone please help me understand the differnce between the dielectric torque and the electric torque. How does the electric torque couple with spontaneous ?

Thank you
 
Physics news on Phys.org
  • #2

Thank you for your question. I would be happy to help clarify the difference between dielectric torque and electric torque in the context of ferroelectric materials.

Dielectric torque refers to the torque (rotational force) that is generated when an electric field is applied to a material. This torque is a result of the polarization of the material, which is the separation of positive and negative charges within the material. In ferroelectric materials, the dielectric torque is a key factor in their unique properties, as it can cause the material to switch between different polarizations in response to an electric field.

On the other hand, electric torque refers to the torque that is generated by the coupling between the material's spontaneous polarization and an external electric field. In ferroelectric materials, the spontaneous polarization is a result of the material's crystal structure and can exist even in the absence of an external electric field. When an electric field is applied, the electric torque couples with the spontaneous polarization, causing the material to rotate or switch between different polarizations.

In summary, dielectric torque is generated by the applied electric field, while electric torque is a result of the coupling between the applied electric field and the material's spontaneous polarization. I hope this helps to clarify the difference between the two terms.
 

1. What are liquid crystals?

Liquid crystals are a unique state of matter that exhibit properties of both liquids and solids. They have a distinct arrangement of molecules that give them the ability to flow like a liquid, while maintaining some degree of order like a solid.

2. What is dielectric torque?

Dielectric torque is a force that acts on a liquid crystal due to an external electric field. This force causes the liquid crystal molecules to align with the direction of the electric field.

3. How does electric torque affect liquid crystals?

Electric torque is a force that acts on a liquid crystal due to an internal electric field. This force causes the liquid crystal molecules to rotate around their long axes, resulting in changes in the orientation of the molecules and the overall properties of the liquid crystal.

4. What are the applications of liquid crystals?

Liquid crystals have a wide range of applications, including in display technologies such as LCD screens, as well as in sensors, optical devices, and biomedical tools. They are also used in research to study molecular interactions and phase transitions.

5. How are liquid crystals used in display technologies?

Liquid crystals are used in display technologies such as LCD screens due to their ability to change their orientation in response to electric fields. This allows for the manipulation of light and the creation of images on the screen. By applying electric torque, the liquid crystal molecules can be aligned in specific patterns to produce different colors and images.

Similar threads

  • Electromagnetism
Replies
6
Views
767
  • Introductory Physics Homework Help
Replies
14
Views
498
  • Electromagnetism
Replies
1
Views
2K
Replies
7
Views
1K
Replies
1
Views
991
  • Mechanical Engineering
Replies
7
Views
1K
  • Electrical Engineering
Replies
2
Views
2K
  • Electromagnetism
Replies
10
Views
5K
Replies
9
Views
2K
Replies
2
Views
2K
Back
Top