J. Phys. II France
Volume 7, Numéro 5, May 1997
Page(s) 729 - 741
DOI: 10.1051/jp2:1997155
J. Phys. II France 7 (1997) 729-741

Effect of Fluctuations on the Freezing of a Colloidal Suspension in an External Periodic Potential

J. Chakrabarti1 and Supurna Sinha2

1  Department of Physics, Indian Institute of Science, Bangalore 560 012, India
2  Jawaharlal Nehru Centre for Advanced Scientific Research and Centre for Theoretical Studies, Indian Institute of Science, Bangalore 560 012, India

(Received 20 August 1996, received in final form 4 February 1997, accepted 7 February 1997)

We incorporate the effects of fluctuations in a density functional analysis of the freezing of a colloidal liquid in the presence of an external potential generated by interfering laser beams. A mean-field treatment, using a density functional theory, predicts that with the increase in the strength of the modulating potential, the freezing transition changes from a first order to a continuous one via a tricritical point for a suitable choice of the modulating wavevectors. We demonstrate here that the continuous nature of the freezing transition at large values of the external potential ${V_{\rm e}}$ survives the presence of fluctuations. We also show that fluctuations tend to stabilize the liquid phase in the large ${V_{\rm e}}$ regime.

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