Europhys. Lett.
Volume 72, Number 4, November 2005
Page(s) 583 - 589
Section Condensed matter: structural, mechanical and thermal properties
Published online 19 October 2005
Europhys. Lett., 72 (4), pp. 583-589 (2005)
DOI: 10.1209/epl/i2005-10288-6

Monte Carlo simulation of string-like colloidal assembly

Y. Norizoe and T. Kawakatsu

Department of Physics, Tohoku University - Sendai 980-8578, Japan

received 2 June 2005; accepted in final form 27 September 2005
published online 19 October 2005

We study structural phase transition of polymer-grafted colloidal particles by Monte Carlo simulations on hard spherical particles. The interaction potential, which has a weak repulsive step outside the hard core, was validated with use of the self-consistent field calculations. With this potential, canonical Monte Carlo simulations have been carried out in two and three dimensions using the Metropolis algorithm. At low temperature and high density, we find that the particles start to self-assemble and finally align in strings. By analyzing the cluster size distribution and string length distribution, we construct a phase diagram and find that this string-like assembly is related to the percolation phenomena. The average string length diverges in the region where the melting transition line and the percolation transition line cross, which is similar to Ising spin systems where the percolation transition line and the order-disorder line meet on the critical point.

64.60.Ak - Renormalization-group, fractal, and percolation studies of phase transitions.
61.43.Er - Other amorphous solids.
82.70.Dd - Colloids.

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