title: Crossover parametric equation of state for Ising-like systems.
abstract: We present a parametric equation for the thermodynamic properties in the critical region of three-dimensional Ising-like systems which include fluids and fluid mixtures. The equation of state incorporates a crossover from singular Ising behavior asymptotically close to the critical point to classical (mean-field) behavior further away from the critical point, characterized by two physical crossover parameters: a coupling constant related to the strength and range of molecular interactions and a "cutoff" wave number for the critical fluctuations. In the asymptotic Ising limit, the crossover equation reproduces the most recent theoretical estimates for the universal ratios of the leading and correction-to-scaling critical amplitudes. The equation has been tested by comparing it with recent experimental thermodynamic-property data for 3He near its vapor-liquid critical point.
authors.affiliation: Institute for Physical Science and Technnology and Department of Chemical Engineering, University of Maryland, College Park 20742, USA.
authors.forename: V A
authors.initials: VA
authors.lastname: Agayan
authors.forename: M A
authors.initials: MA
authors.lastname: Anisimov
authors.forename: J V
authors.initials: JV
authors.lastname: Sengers