Hexatic order and liquid density fluctuations.

We study the evolution of liquid structure factors with changing bond- orientational (hexatic) order. The form of the radial structure factor is found to depend strongly on the mean square amplitude of fluctuations in the hexatic order parameter. The density and correlation length of the liquid, measured near the hexatic-isotropic transition, are explicitly related to the specific heat. The effects of substrates on the hexatic ordering process in two dimensions are also examined.