One-to-one correspondence between slowly decaying interfacial profiles and reflectivity

Abstract

A variety of mechanisms give rise to interfacial profiles which approach their bulk values asymptotically like ${\mathrm{az}}^{\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\mu}}}$; for most of them 0<\ensuremath{\mu}\ensuremath{\le}2. In these cases the exponent as well as the amplitude can be determined uniquely by reflectivity measurements slightly above the angle of total external reflection.