Restricted Dislocation Motion in Crystals of Colloidal Dimer Particles

Abstract

At high area fractions, monolayers of colloidal dimer particles form a degenerate crystal (DC) structure in which the particle lobes occupy triangular lattice sites while the particles are oriented randomly along any of the three lattice directions. We report that dislocation glide in DCs is blocked by certain particle orientations. The mean number of lattice constants between such obstacles is 4.6 +/- 0.2 in experimentally observed DC grains and 6.18 +/- 0.01 in simulated monocrystalline DCs. Dislocation propagation beyond these obstacles is observed to proceed through dislocation reactions. We estimate that the energetic cost of dislocation pair separation via such reactions in an otherwise defect free DC grows linearly with final separation, hinting that the material properties of DCs may be dramatically different from those of 2-D crystals of spheres.

References in corpus (4)

• An RVB phase in the triangular lattice quantum dimer model
• Pocket Monte Carlo algorithm for classical doped dimer models
• Effect of Grain Geometry on Angle of Repose and Dynamics
• The Influence of Shape on Ordering of Granular Systems in Two Dimensions

Cited by in corpus (14)

• The Physics of the Colloidal Glass Transition
• Orientationally Glassy Crystals of Janus Spheres
• Degenerate Quasicrystal of Hard Triangular Bipyramids
• Glassy Dislocation Dynamics in 2-D Colloidal Dimer Crystals
• Differently Shaped Hard Body Colloids in Confinement: From passive to active particles
• Local melting attracts grain boundaries in colloidal polycrystals
• Collective Sliding States for Colloidal Molecular Crystals
• Dimer Covering and Percolation Frustration
• Grain splitting is a mechanism for grain coarsening in colloidal polycrystals
• Orientational Dynamics of Fluctuating Dipolar Particles Assembled in a Mesoscopic Colloidal Ribbon
• Orientational ordering and correlations in a quasi-one-dimensional hard-dumbbell fluid
• Structural diversity and the role of particle shape and dense fluid behavior in assemblies of hard polyhedra
• Morphology, Polarization Patterns, Compression, and Entropy Production in Phase-Separating Active Dumbbell Systems
• Non-Gaussian Rotational Diffusion and Swing Motion of Dumbbell Probes in Two Dimensional Colloids