EFFECTS OF SURFACE ENHANCEMENT ON FLUCTUATION-INDUCED INTERACTIONS

We examine the fluctuation-induced interaction energy DELTAf between the surfaces of a layered hexatic film within a quadratic-functional-integral approach. Both discrete and continuum formulations are studied. We find large corrections to the asymptotic behavior DELTAf(l) is-proportional-to l-2 for finite l, where l is the film thickness. A small field becomes relevant beyond a length scale xi(h), while an enhanced surface Frank constant is irrelevant above a length xi(K). Possible relevance of these results to recent experiments on layer-by-layer surface ordering in liquid-crystal films is discussed.