Elastically Disordered Perfect Colloidal Crystals
ORAL
Abstract
We use spherical microgel colloidal particles to study lattice dynamics in a three-dimensional crystal using optical microscopy. We find that the local bond length fluctuations vary by as much as 75{\%} from bond to bond despite less than 2{\%} fluctuations in the equilibrium bond lengths. We show how to calculate the low-energy eigenmodes and the density of states in the presence of the strong heterogeneity. We find that the lowest energy eigenmodes are dominated by a few long-wavelength planewaves, and the density of states shows Debye-like behavior at low energy. This work has been partially supported by the NSF through Grants DMR-0619424 and DMR-0645596, by ACS-PRF and Alfred P. Sloan foundation.
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Authors
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Deniz Kaya
Department of Chemical Engineering
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N.L. Green
Department of Chemical Engineering
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C.E. Maloney
Carnegie Mellon, Carnegie Mellon University, Department of Civil \& Environmental Engineering, Deparment of Civil and Environmental Engineering
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M.F. Islam
Department of Chemical Engineering and Department of Materials Science \& Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, Departments of Chemical Engineering, Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213