| We study strained crystals and glasses comprised of hard-sphere colloidal particles. We find that strained colloidal crystals exhibit dislocations that show remarkable similarities to dislocations in atomic crystals. Using a laser diffraction microscopy setup and confocal microscopy, we are able to visualize the nucleation, motion and interaction of these defects on a range of length scales down to the particle scale. Confocal microscopy allows us to determine the positions of the individual particles in the solid phases in three dimensions, and to determine the local strain field associated with the particle displacements. This opens a unique window on the interplay between applied and local strain, and thermal fluctuations that governs defect formation. |
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