Freezing of a two-dimensional binary hard-disk liquid: A density-functional approach

The freezing of a two-dimensional binary hard-disk (BHD) liquid is investigated using an alternative density-functional approach. Our calculation indicates that within disk diameter ratios 0.81, a BHD liquid freezes into a substitutionally disordered triangular lattice via a weak first-order transition, in contrast to the hexatic phase (for 0.80.9) predicted from a computer-generated random-packing model. the BHD liquid also does not show the eutectic phase diagram found for binary hard spheres in three dimensions, but only spindle or azeotrope phase diagrams.