Crystallization of tetrahedral patchy particles in silico

Area of Science:

• Materials Science
• Computational Chemistry
• Statistical Mechanics

Background:

• Understanding the self-assembly of particles with directional interactions is crucial for designing novel materials.
• Competition between crystallization and glass formation dictates the final structure and properties.

Purpose of the Study:

• To investigate the competition between glass formation and crystallization in open tetrahedral structures.
• To analyze the influence of interaction parameters, specifically patch width and interaction range, on the self-assembly outcome.

Main Methods:

• Simulations of particles with tetrahedral patchy interactions.
• Analysis of potential parameters, including interaction range and angular patch width.
• Evaluation of temperature and density dependence of chemical potential for fluid and crystal phases.

Main Results:

• Open crystal structures (e.g., cubic and hexagonal diamond) spontaneously form when the angular width of patches is less than approximately 30°.
• Adjusting patch width differentially affects the fluid and crystal phases.
• For small-width patches, the driving force for self-assembly increases rapidly upon cooling.
• For large-width patches, crystallization is hindered, leading to dynamic arrest and network glass formation.

Conclusions:

• The angular width of tetrahedral patches is a critical parameter controlling the self-assembly pathway.
• Narrow patches promote crystallization into open diamond-like structures.
• Wider patches favor glass formation over crystallization, highlighting the role of dynamic arrest.