Department of Physics Papers

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Journal Article

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We studied the two-dimensional freezing transitions in monolayers of microgel colloidal spheres with short-ranged repulsions in video-microscopy experiments, and monolayers of hard disks, and Yukawa particles in simulations. These systems share two common features at the freezing points: (1) the bimodal distribution profile of the local orientational order parameter; (2) the two-body excess entropy, s2, reaches −4.5 ± 0.5 kB. Both features are robust and sensitive to the freezing points, so that they can potentially serve as empirical freezing criteria in two dimensions. Compared with the conventional freezing criteria, the first feature has no finite-size ambiguities and can be resolved adequately with much less statistics; and the second feature can be directly measured in macroscopic experiments without the need for microscopic information.


Suggested Citation:
Z. Wang, W. Qi, Y. Peng, A.M. Alsayed, Y. Chen, P. Tong and Y. Han. (2011). "Two features at the two-dimensional freezing transitions." The Journal of Chemical Physics. 134, 034506.

© 2011 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in The Journal of Chemical Physics and may be found at

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Date Posted: 27 January 2011

This document has been peer reviewed.