Tailored morphologies in two-dimensional ferronematic wells.

Area of Science:

• Physics
• Materials Science
• Soft Matter Physics

Background:

• Nematic liquid crystals and magnetic nanoparticles are key components in advanced materials.
• Understanding their coupled behavior is crucial for developing novel functional systems.
• Spontaneous magnetization in such systems offers unique possibilities without external fields.

Purpose of the Study:

• To investigate the spontaneous magnetization and defect formation in a magnetic nanoparticle-nematic system.
• To explore how geometry, boundary conditions, and nanoparticle-nematic coupling influence system morphology.
• To demonstrate the potential for creating tailored, multistable systems with controllable singularities and interfaces.

Main Methods:

• Numerical simulations of a dilute uniform suspension of magnetic nanoparticles in a nematic-filled micron-sized shallow well.
• Analysis of tangent boundary conditions and the coupling between magnetic nanoparticles and the host nematic medium.
• Characterization of stable nematic and magnetization morphologies, including domain walls and defects.

Main Results:

• The system exhibits spontaneous magnetization without applied magnetic fields.
• Geometry and boundary conditions induce stable nematic and magnetization morphologies.
• Domain wall locations are tunable via coupling and material properties.
• Stable interior and boundary nematic defects can be precisely controlled by coupling.

Conclusions:

• Tailored morphologies, including controllable defects and domain walls, are achievable through nanoparticle-nematic coupling.
• These findings are not observed in uncoupled systems.
• The developed system offers potential for applications in multistable devices utilizing singularities and stable interfaces.