Internal-stress-induced solid-solid transition involving orientational domains of anisotropic particles

Area of Science:

• Soft Matter Physics
• Materials Science
• Statistical Mechanics

Background:

• Anisotropic colloidal particles, like Janus particles, serve as models for anisotropic atoms and molecules.
• Janus particles in single crystals undergo collective rotation and form polycrystalline domains with increasing temperature.
• This transition preserves translational order but loses orientational order, with its mechanism remaining unclear.

Purpose of the Study:

• To elucidate the mechanism behind the unusual solid-solid transition in Janus particle crystals.
• To identify the key factors inducing the loss of orientational order while maintaining translational order.

Main Methods:

• Theoretical analysis using anisotropic elasticity theory.
• Derivation of the transition condition and domain boundary directions by analyzing strain energy and stress.
• Validation through molecular dynamics simulations.

Main Results:

• The solid-solid transition is induced by internal strains.
• The coupling between particle orientation and position is crucial for the transition.
• Theoretical predictions for transition conditions and domain boundaries align with simulation results.

Conclusions:

• Internal strains and orientation-position coupling drive the solid-solid transition in Janus particle systems.
• The anisotropic elasticity theory successfully explains the observed transition mechanism.
• This transition mechanism is potentially applicable to other anisotropic particle systems.