Evidence for dipole surface orientational order at critical interfaces

At the critical interface of dipolar systems theory predicts that the amplitude of the surface orientational order alpha(2)(z) approximately m(*4)d(2)v(z)/dz(2), where m(*) is a reduced dipole moment and v(z) is the local composition at position z within the interface. We find quantitative agreement with these predictions for two different critical binary liquid mixtures composed of a highly polar and a nonpolar component.