Fredericks transitions in biaxial nematics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Chemical Physics

Background:

• Understanding biaxial nematic liquid crystals (NLCs) and their textural transformations in external fields is crucial for applications.
• Current theoretical approaches face challenges in minimizing multi-parametric free energy due to non-linear constraints.

Purpose of the Study:

• To develop a new theoretical framework for analyzing textural transformations in biaxial NLCs.
• To overcome limitations of direct free-energy minimization for biaxial NLCs.

Main Methods:

• Utilized the concept of "angular velocity" to describe the order parameter's rotations and internal texture curvature.
• Developed a method to resolve non-linear constraints in free-energy minimization.
• Derived equations for one-dimensional textures of biaxial NLCs in external fields.

Main Results:

• Successfully resolved constraints in free-energy minimization for biaxial NLCs.
• Obtained a set of equations to determine all possible one-dimensional textures in external fields.
• Calculated critical fields for basic textural transition configurations.

Conclusions:

• The "angular velocity" method offers an effective way to study biaxial NLC textures.
• The findings can aid in determining the intrinsic biaxiality of liquid crystalline materials.