J. Phys. I France
Volume 4, Numéro 1, January 1994
Page(s) 77 - 85
DOI: 10.1051/jp1:1994121
J. Phys. I France 4 (1994) 77-85

Line tension at wetting: finite-size effects and scaling functions

J. O. Indekeu and H. T. Dobbs

Laboratorium voor Vaste Stof-Fysika en Magnetisme, Katholieke Universiteit Leuven, B-3001 Leuven, Belgium

(Received 23 June 1993, accepted in final foret 8 October 1993)

We study the effect of finite system size on the tension $\tau$ of a three-phase contact line. This is especially important in systems with forces that are sufficiently long-ranged for $\tau$ to diverge in the thermodynamic limit. Near wetting phase transitions we propose an anisotropic finite-size scaling hypothesis, which takes into account the effect of thermal capillary-wave fluctuations. The singular behaviour of $\tau$ near a first-order wetting transition is analyzed. Scaling functions are calculated explicitly in the mean-field regime, which includes the physically most common systems with van der Waals forces in dimension d = 3.

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