title: Hexatic phase in the two-dimensional Gaussian-core model.
abstract: We present a Monte Carlo simulation study of the phase behavior of two-dimensional classical particles repelling each other through an isotropic Gaussian potential. As in the analogous three-dimensional case, a reentrant-melting transition occurs upon compression for not too high temperatures, along with a spectrum of waterlike anomalies in the fluid phase. However, in two dimensions melting is a continuous two-stage transition, with an intermediate hexatic phase which becomes increasingly more definite as pressure grows. All available evidence supports the Kosterlitz-Thouless-Halperin-Nelson-Young scenario for this melting transition. We expect that such a phenomenology can be checked in confined monolayers of charge-stabilized colloids with a softened core.
authors.affiliation: Università degli Studi di Messina, Dipartimento di Fisica, Contrada Papardo, Messina, Italy. Santi.Prestipino@unime.it
authors.forename: Santi
authors.initials: S
authors.lastname: Prestipino
authors.forename: Franz
authors.initials: F
authors.lastname: Saija
authors.forename: Paolo V
authors.initials: PV
authors.lastname: Giaquinta