Evidence was found, from isothermal-isobaric molecular dynamics simulations, of hexatic phase formation in Lennard-Jones binary substitutional random arrays. The hexatic phase was analogous to those predicted by the Kosterlitz-Thouless theory of melting, which was characterized by short-range translational order and quasi long-range orientational order. At the crystal-to-hexatic phase transition, dislocation pairs were observed to unbind into isolated dislocations. Further disordering of the hexatic phase did not lead to the dissociation of dislocations into disclinations. The dislocations instead became clustered, and formed dislocation networks which resulted in the formation of amorphous phases.

Evidence of Hexatic Phase Formation in Two-Dimensional Lennard-Jones Binary Arrays. M.Li, W.L.Johnson, W.A.Goddard: Physical Review B, 1996, 54[17], 12067-72