Restricted Dislocation Motion in Crystals of Colloidal Dimer Particles

Authors

Sharon J. Gerbode, Harvey Mudd CollegeFollow
Stephanie H. Lee, Cornell University
Chekesha M. Liddell, Cornell University
Itai Cohen, Cornell University

Document Type

Article

Department

Physics (HMC)

Publication Date

8-2008

Abstract

Received 2 April 2008; published 1 August 2008; corrected 1 October 2008

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 Z̅ _exp=4.6±0.2 in experimentally observed DC grains and Z̅ _sim=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.

Comments

This article is also available from the American Physical Society at http://link.aps.org/doi/10.1103/PhysRevLett.101.058302.

Corrections are available for download below and from the American Physical Society at http://link.aps.org/doi/10.1103/PhysRevLett.101.159902.

Rights Information

© 2008 American Physical Society

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DOI

10.1103/PhysRevLett.101.058302

Recommended Citation

S. J. Gerbode, S. Lee, C. Liddell, and I. Cohen, “Restricted dislocation motion in crystals of colloidal dimer particles” Phys. Rev. Lett. 101, 058302 (2008). doi: 10.1103/PhysRevLett.101.058302