J. Phys. I France
Volume 5, Numéro 9, September 1995
Page(s) 1161 - 1178
DOI: 10.1051/jp1:1995189
J. Phys. I France 5 (1995) 1161-1178

Criticality of Lamellar Surfaces by Conformational Degrees of Freedom

B. Bassetti1, G. Mazzoletti1 and P. Jona2

1  Universitá degli Studi di Milano, Dipartimento di Fisica, Via Celoria 16, 20123 Milano, Italy
2  Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20123 Milano, Italy

(Received 10 November 1994, revised 11 April 1995, accepted 29 May 1995)

A new model for lamellar surfaces formed by anisotropic molecules is proposed. The molecules have internal degrees of freedom, associated with their flexible section of lenght N at zero temperature. We obtain a 2D non-standard six-vertex model, which is exactly soluble and exhibits a finite order transition. The order and the character of the transition are determined by the dominant term in the 1/N-expansion of the interaction energy. The dependence of the critical temperatures on N is, instead, determined by the non-leading terms in the same expansion.

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