title: Melting and evaporation in classical two-dimensional clusters confined by a Coulomb potential.
abstract: The thermal properties of a two-dimensional classical cluster of negatively charged particles bound by a punctual positive charge are presented. The melting phenomenon is analyzed and the features which characterize such a solid-liquid transition are highlighted. We found that the presence of metastable states strongly modifies the melting scenario, and that the melting temperature of the system is determined by the height of the saddle point energy separating the ground state and the metastable state. Due to the particular type of confinement potential considered in this paper, we also found that, at sufficiently large temperature, the cluster can become thermally ionized.
authors.affiliation: Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Campus do Pici, 60455-760 Fortaleza, Ceará, Brazil. wandemberg@fisica.ufc.br
authors.forename: W P
authors.initials: WP
authors.lastname: Ferreira
authors.forename: F M
authors.initials: FM
authors.lastname: Peeters
authors.forename: G A
authors.initials: GA
authors.lastname: Farias