corner
corner

Phys. Rev. Lett. 101, 058302 (2008) [4 pages]

Restricted Dislocation Motion in Crystals of Colloidal Dimer Particles

Download: PDF (1,325 kB) Buy this article Export: BibTeX or EndNote (RIS)

Sharon J. Gerbode1, Stephanie H. Lee2, Chekesha M. Liddell2, and Itai Cohen1
1Physics, Cornell University, Ithaca, New York 14853, USA
2Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA

See Also: Publisher's Note

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.

© 2008 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevLett.101.058302
DOI:
10.1103/PhysRevLett.101.058302
PACS:
82.70.Dd, 61.72.Ff, 83.10.Pp

See Also

Publisher's Note: Sharon J. Gerbode, Stephanie H. Lee, Chekesha M. Liddell, and Itai Cohen, Publisher’s Note: Restricted Dislocation Motion in Crystals of Colloidal Dimer Particles [Phys. Rev. Lett. 101, 058302 (2008)], Phys. Rev. Lett. 101, 159902 (2008).