Surface coupling effect on wetting and layering transitions

Abstract

The effect of the surface coupling $J_s$ on the dependency of the layering transition temperature $T_L$ as a function of the thickness $N$, of a spin-1/2 Ising film, is studied using the mean field theory. It is found that for $J_s$ greater than a critical value ($J_{sc}=1.30$), the layering transition temperature decreases when the film thickness $N$ increases for any values of the surface magnetic field $H_s$. While, for $J_s<J_{sc}$, the behaviour of the layering transition temperature $T_L$, as a function of $N$, depends strongly on the values of $H_s$. Indeed, we show the existence of three distinct behaviours of $T_L$, as a function of the film thickness $N$, separated by two critical surface magnetic fields $H_{sc1}$ and $H_{sc2}$, namely: $(i)$ for $H_s<H_{sc1}$, $T_L$ increases with $N$; $(ii)$ for $H_{sc1}<H_s<H_{sc2}$, $T_L$ increases for small values of $N$, and decreases for large value ones; (iii) while for $H_s>H_{sc2}$, $T_L$ decreases with increasing the film thickness. Furthermore, depending on the values of $J_s$, the wetting temperature $T_w(T_w=T_L$ when $N\to \infty$ for a given material), can be greater or smaller than the layering transition temperature of a film of thickness $N$ of the same material.

9 pages Latex, 6 figures PS

References in corpus (1)

• Edge wetting of an Ising three-dimensional system

Cited by in corpus (3)

• A Monte Carlo study of random surface field effect on layering transitions
• Interface disorder and layer transitions in Ising thin films
• Effect of the inhomogeneity of substrate on layering transitions