Hexatic phase

The hexatische phase is a lying between liquid and crystal phase in two-dimensional systems. They can be described by two order parameters, one of which, the translational order is short range, while the second, the orientational order is quasi- long range.

The existence of the phase was predicted by John Michael Kosterlitz and David J. Thouless and Bertrand Halperin, David R. Nelson and Young through their theoretical work for melting in two dimensions. Here, the phase transition is explained by the binding of topological defects, the dislocations and disclinations.