title: Coarse molecular-dynamics analysis of an order-to-disorder transformation of a krypton monolayer on graphite.
abstract: The thermally induced order-to-disorder transition of a monolayer of krypton (Kr) atoms adsorbed on a graphite surface is studied based on a coarse molecular-dynamics (CMD) approach for the bracketing and location of the transition onset. A planar order parameter is identified as a coarse variable, psi, that can describe the macroscopic state of the system. Implementation of the CMD method enables the construction of the underlying effective free-energy landscapes from which the transition temperature, T(t), is predicted. The CMD prediction of T(t) is validated by comparison with predictions based on conventional molecular-dynamics (MD) techniques. The conventional MD computations include the temperature dependence of the planar order parameter, the specific heat, the Kr-Kr pair correlation function, the mean square displacement and corresponding diffusion coefficient, as well as the equilibrium probability distribution function of Kr-atom coordinates. Our findings suggest that the thermally induced order-to-disorder transition at the conditions examined in this study appears to be continuous. The CMD implementation provides substantial computational gains over conventional MD.
authors.affiliation: Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Amat
authors.forename: Marco
authors.initials: M
authors.lastname: Arienti
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Fonoberov
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Kevrekidis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Maroudas